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What settings to use on video rendering from image sequence?
So I exported my image sequence as 4k res png files from Eevee, 270 frames, and now I need to create a video from it. I couldn't find any reasonable information explaining everything about the process so here's my noob questions:
Do I need the same render settings when rendering the video as the render settings when rendering the image sequences ? Does sample count even matter when I already exported the images as 90 samples, should I put the same samples when rendering the video ?
My images are 4k resolution, should I put 4k resolution in the output of the video render as well ?
Do these settings even matter when I already have the images ? And if not, which settings matter when rendering the video ? Should I render the video from the same scene file or should I load a new one ?
I tried rendering my images as a video but the video is all jagged with all sorts of artifacts and the video is on a small screen resolution even though I put 4k resolution ?
Thanks in advance for anyone who can answer my questions !

Not necessarily. You would need to change the filetype to mp4 or any other video format though.
I just checked and the sample count doesn't seem to matter for rendering from VSE.
Yes, the resolution matters.
No, it doesn't matter. You can render all the pngs and compile them to a video in another blend file.
I don't know the exact issue but you should check the color management of the scenes. I think Filmic is enabled by default for rendering which is not what you might want. Also, rendering from VSE takes a lot of time and it is not very flexible. If you want to do some heavy editing, I would suggest other programs specifically designed for this purpose, like Premiere or DaVinci Resolve (which is free).

Thanks for your answers ! The color management seems to mess up with the end result a lot. High contrast for example gets applied on both when rendering my images and when rendering from VSE. I played around but nothing seem to work, my video is still jagged and too dark. I will give DaVinci Resolve a try, thanks for your suggestion !

Glad to help you :)

Wait wait wait... Are you rendering a 3D scene with Cycles/eevee or have you already rendered your 3D scene into an image sequence and just want to have those pictures turned into a video file ? In the second case, you are not doing any 3D rendering, so 3D render settings don't matter.


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Why physics simulation works in viewport but not in final render?
I'm trying to render an animation 449 frames long. The animation part of the render is showing but the rigid body simulations are not visible. The simulation setting is set to 600 frames I tried deleting the cache multiple times and bake all dynamics again, I tried restarting blender, I double checked everything and I still cannot render the simulation ? Any other reasons the sim is not playing on final render ? I couldn't find an answer here so I'm posting the question. I think its a bug but might be something else ? Thanks

I tried messing with the world settings a bit more and now my whole simulation is not running at all even in the viewport... I deleted the Rigid Body World and then created new and selected Rigid Body World for my Collection and Rigid Body Constraints for the Constraints, since that's what was generated by Blender, then I delete all bakes then bake all dynamics and it doesnt work... I tried moving the objects with rigib bodies into a new collection altogether, which enabled the simulation on the viewport but everything just collapses and flies everywhere even if it's a passive rigid body

provide your blend file so we can help you

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

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Eevee cannot finish a render
Eevee just won't render my project. I have 2 Terrains in the scene with 6 subsurf divisions and a displacement modifier with image texture for the shape of the terrain and I have 3 nebulae as a background on the sky which are made from principled volume and one more principled volume which is a big box for everything in the scene. I have other objects but I have separated them by render layers so the system can digest it, but it still crashes... When I render with 1 sample it does the job, even though when I click render it still stays blank for 5-6 minutes and I cannot do anything else then magically the render appears, but when I go with 100 samples or more it just won't work it crashes... and I need more than 100 samples because the scene is fairly complex. I tried renderfarm but again the file won't go even through a renderfarm... I need the volumetrics to be at 2px tile size and I think this is clogging the whole render, or the sub divisions on my 2 terrains.
The scene gets to about 9 million faces, which I guess is too much but still I thought it will take time but it just keeps on crashing and not even through a render farm ? How is this even possible
Cannot split the volume of the scene and the terrains because eevee doesn't allow for indirect lights and reflections when you split the scene by render layers.
On the viewport everything runs okay at rendered view but when I try to render it doesn't work...
Is there anyway to go around this problem or I need to sacrifice heavily on quality ?
I spent a whole day + today as well trying to figure out a way to render this ...
Thanks

Viewport render quality is automatically reduced. I think it is indeed the high volumetrics. There is a reason they allow you to lower the volumetric resolution: so you don’t swamp your RAM and processing time.

You're right I just fixed it by lowering the sample count on the volumetrics tab from 256 to 100 and it worked like magic. I still keep tile size at 2px and it works. So the main problem was the sample count on the volumetrics.

all right! Please add your answer to the question so future researchers can find it. Thanks!

Lowering the sample count on the volumetrics tab fixes the issue

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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Lights not working
So the lights on my scene are not working at all, I point light, spot, sun, area nothing works

I tried also changing the values and the radius of the lights not working at all scene light are also turned on
Won't work on viewport and it won't work on rendering
My object has a refractive shader on it and if I crank up the world lights a bit I can see my object but the spot light still won't work
Never happened before ? Any solutions ?
Thanks

I see 2.93.4 on Windows 10? Is this happening with a single blend file or all your files? If it's a single file, perhaps you can share it with us?

Does diffuse shader work?

it's windows 10 yeah, other files are okay I guess I'll just try and move all my objects to a new file, but it's weird why the lights won't work...

can u provide your blend file?

First make sure:

The World space is right. If the light is to far away from the object, it doesn't light anything up.

The light is in the same collection as the "lit" object (or linked to it)

Light objects don't need to be in the same collection as objects

Thanks for the reply!
But both options won't work, it doesn't matter where I put the light relative to the object, even If I put it on top of it still won't work


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Mesh is looking really sharp when in render or material preview mode
When I'm in materials preview mode or render mode in Eevee my character mesh looks extremely sharp I've smooth the mesh already but it still appears sharp...

When I'm in solid mode it looks smooth like it should be... ?

Well, did you turn off the viewability of any modifier for any view?

All modifiers are applied already

Well, I'm not exactly sure what's wrong, then. Would you mind to share the blend file?

I found a semi solution I copy paste my model into another new scene and it fixes the problem but still not sure why this happened at all...

I guess it's just a bug.

Yeah ... Thanks for your response tho ! Appreciate

How exactly did you 'smooth the mesh'?

Copy paste into a new file or delete and create a new material

Happened to me after trying to bake normal map. The solution is to delete the old material then create a new one or copy paste your mesh into a new scene


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Viewport is becoming slower the more I work on a scene
Viewport is becoming slower and slower the more I use the scene regardless of the complexity of the scene.
So I have this problem ever since I started working with Blender, more than a year now, and I've notice that if I'm playing with a scene for a while the scene just becomes unusable for no logical reason whatsoever.
It becomes so slow that I can barely move basic objects even a default cube in wireframe mode...
It feels as if there is some sort of scene cache file that needs to be cleaned up ?
The workaround:
If I copy all of the objects in the scene and put them into a new scene the lag disappears and the viewport then becomes as responsive as new.
My question is why is this happening ? Is it just me ? Is there a way to fix or troubleshoot this issue ?
Thanks.

Can you share you blend file in the post so we can see what is up with it? There could be a number of reasons.

I have used blender for a long time and I have never had this problem. You can show some hardware information and blender preference system settings to us.

Usually It's due to a weak system or a small amount of ram, I always had this problem when using a weak laptop. The only thing that helped was restarting the blender (close it and reopen - should help)


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Verify if model is ok for 3D Printing?
I have made a model for 3d printing, I knowthere are some checks I need to do in order to have a good print, but I cant find a place where to see all the bullet points to check.
Is there a page or document where i can see all the things i should have in mind when sending a model to print?
Thanks.

In the user prefs > add-ons > mesh > 3D Print Toolbox __ options are in the side panel in Object or Edit mode.


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Startup cube not display as other objects

I started to learn blender on Dell Latitude E7450 with Intel Corei7 in order to participate a contest but after the laptop crashed I switched to Hp Protect Smart with AMD A10-5750M APU with Radeon HD Graphic 2.50 Ghz. I first encountered this problem when running a blender on HP.(If I clicked on cube then it shows the edges).When I switched to the HP I first encountered this problem.Startup cube not show in object mode but if highlight all its vertices then it is displayed in semi-transparent view.After this manipulation, the object is displayed in a translucent manner.It is not over.New objects that i created was same as it except the circle.I don't know how to explain it but I'll show you.What it is?I also became aware of this problem when importing a fbx character model]8Shall you help me please?Here are some similar questions that can help you:
Default cube not displayed
https://blenderartists.org/t/solved-solid-view-not-showing-the-default-cube/549643/9

Hello :). Since the A10-5750M APU is from March 2013, there might be some issues with compatibility. Perhaps older Blender versions will work better.

Thank you very much for that.It works


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AMD Radeon R7 450 card not detected
Ok so the official blender site says that if an amd card has gcn 1st gen or newer architecture, the amd card is compatible

And my card i.e. AMD Radeon R7 450 has GCN 1st Gen architecture as mentioned here

then also my Blender isnt recognising the card when i switch to open cl. That is a whole 4gb og GPU memory wasted
Can anybody pls guide me as i have tried all available options
Thanks in advance

Your GPU fulfills the minimum requirements for running Blender 2.8x. However, it does not meet the requirements for GPU rendering.

if u are familiar with sheepit, it can use my gpu for rendring other peoples file using blender application. ow is it then sheepit is able to identify the gpu and render through it via blender but my native isnt able to identify it ?

I haven't checked, but it's likely because SheepIt uses multiple Blender versions and projects for Blender 2.79 are rendered with that specific version. The older version had lower requirements and allows GPU rendering on your hardware. BTW Blender 2.8x is able to identify it, but since it's below the minimum requirements for GPU rendering Blender doesn't list it.

see https://docs.blender.org/manual/en/latest/render/cycles/gpu_rendering.html#supported-hardware


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Rendered image has WEIRD AND GRAINY lighting
I'm trying to make an animation inside Freddy Fazbear's Pizza, but when I rendered the image to see how it looked, I got THIS.
I don't know how the heck this happened. for reference, this is what it looked like before the render.

What's going on and how do I fix it?

Looks like having overlapping objects?

Duplicated geometry causing z-fighting.


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Fluid simulation not working after scaling the domain
So I just notice that If I scale up the domain of the fluid simulation and bake again the fluid it doesn't work... I tried applying the scale and I tried without applying same thing.
Is there any reason why this is happening ?

increase resolution divisions and it will work

Not too sure without more information, I've had similar issues where the domain clearly looks deformed despite the scale being cleared.
Removing the Domain under physics properties and re-adding it to the object still wouldn't work.
My solution to this has been to delete the object and remake the domain. Remember to add your material back onto the new domain if you do this.
I rarely run into this issue. I'm not sure what causes it, but it could be a bug.


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Armature with a shrinkwrap constraint exported as animation data
I guess my question is how to bake the animation data from the Shrinkwrap constraint onto my Armature, but I'm so confused...
So I really want to export from Blender to Marvelous Designer my character and armature and simulate the clothing I made in MD and put it back in blender... But I have a massive problem.
In blender my armature is animated in a very weird way. I have a spring object that is animated using screw and simple deform modifiers. My character's armature is sitting on top of that spring object and a Shrinkwrap constraint is used on the armature to target a suzanne head which has a geometry nodes setup in order to be parented to the Spring Object so they all oscillate together.
(had to be a geometry nodes since the Spring is animated through modifiers)
Main goal is a jack in the box character that jumps out of the box attached to a spring.
But I exported my armature and character as an alembic file into MD then I made clothing I simulated and then I found out that the simulation from this alembic export only includes the armature's bone animation and doesn't include the shrinkwrap constraint data... So I want all of the animation data to be included in in my exported alembic, the whole character oscillating on the spring and the animation from the bones all of this somehow baked or transformed into a single line of animation data that is able to be transferred into MD.
How do I achieve this ??? I spend a whole day trying to sort it out no luck ... I really feel like Blender should have a easy way to transform modifiers and constraints data into actual exportable animation data... Thanks !
The full animation which I want to export:

What I'm exporting

So I found out what needs to be done.
I went on action editor and pushed down the armature's action down as a strip
Then I selected armature went on Object -> Animation -> Bake action -> Ticked: Object ,Only Selected Bones, Visual Keying, Clear Constraints
In Short:


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Normal map bake is not seamless after UV unwrapping character
So I UV unwrapped my character first, then I duplicated it to use as a cage, I went on sculpting n inflated the cage mesh a bit, so it doesn't intercept with the high res sculpt that I want to extract normals from, then I bake normals and this is the result:

If, however, I don't unwrap the low res mesh then it kind of works better, but there are still glitches. So really what's the correct process here ?
Thanks !

hello please share your file: https://pasteall.org/blend/

Bake and read your normal map as non-color data.

Yeah I just realized that one was about to delete this post but I'll leave it in case others do the same mistake... THANKS !

When setting the normal map texture it needs to be set as non colour data before bake


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How to make an object to copy another object's transformations which has been animated through modifiers
So I have a Circle mesh which has a screw modifier + 2 simple deform modifiers (1 to bend on Y axis and one to bend on X axis) Both the Screw Modifier and the Simple deform modifiers are animated in order to create a spring that oscillates across 3 axis.
Now, this spring is moving very nice, but I want to parent another object on top of that spring. How do I do it ?
I cannot parent to a vertex since there is no vertex movement from the original Circle mesh, the whole movement is generated via the modifiers, and the mesh is a simple circle that stays in one place.
I cannot even use constraints because of the same issue.
So I am now forced to animated frame by frame the other object to follow the spring movement, but that takes ages...
Is there any other way I can achieve that ? I'm guessing geometry nodes will be the place to go but how to set up something like this ?
Thanks if anyone have an answer to this.

Here's an idea with geonodes, to pick the last n vertices of your spring and use the mean position of those to place your second mesh... same with normals to get some kind of rotation value. That's assuming when modifiers generate the mesh the last indices are in the end of spring...

a blend file

just to clarify, I ended up using one vertex instead of a few of them as the answer reads, it was way more stable... you can use a face to get the transforms too, just change Domain Size and both Attribute Statistic nodes to use Faces and maybe -Index to 1

Thank you ! Well done I was looking exactly for this

you're welcome, animating screw modifier adds some more fun...


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Cutting hole in ngon adds edges
Hey I know why they are there but is there anyway around having edges visible for cutting holes in ngons? I need it gone because the edges for my flashlight cut is visible on the model.


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Retopoflow needs an update?
So I would like to use Retopoflow for Blender 2.8 but it requires an update by the looks of it, so I searched around for a solution but no luck. Any idea on how to update it? Thanks for your time.

Retopoflow is an add-on that is still in heavy development, and the authors would need to do the work to update it since there are many changes in the way Blender handles graphics now, as well as API changes for python.

So in other words it's still in development for 2.8?

It is still in development, yes. Adapting to 2.8 isn't going to be quick as they are still working on things from 2.79b users as well. My money says that they have it available once we have a stable 2.80a release (we are only in Beta right now).

do you think finishing the 2.8 models and importing them to 2.79b then doing the retopology would be a viable alternative? Thanks for your help.

You can do that, treat 2.79b as your Retopoflow application and then bring the retopo result in 2.8, that is already how I handle it here.

umm thanks for the help for when I transfer the mesh the tools are doing nothing?

The result mesh brought into 2.8 doesn't allow you to edit it? Make sure you have selected the new object. If you are having problems with the import, try saving it as a blend and opening in 2.8.

no I import my mesh I made in 2.8 to 2.79b but it won't let me edit it with retopoflow it's like the tools do nothing

Did you import obj or append the object from the blend file? I get no problem here with append of the object from the 2.80 blend file.

well I don't know what it falls under but I hit control c on the blender 2.8 object and open 2.79b then hit control v and it just showed up.

I can't do that here. I append from the file. Try that.

umm I spawned in a cylinder and Retopoflow wouldn't work for that either. It is also spawning in vertices that do nothing...help please :(

You may need to file a bug report with the retopoflow devs on the github.

But how come no one else has been affected man this has been haunting me for ages I just can't finish anything cause I cant retopologize :(

I see bug fixes come across the mailing list all the time. It works fine in mesh generated in 2.79b for me as well as mesh imported. If you have the latest update for both programs and the add on then file a bug report. This thread was about when the add on was to be updated to 2.8, and that topic is resolved. They answer emails pretty quickly, so be ready to give them an example file.

Oh what version of Retopoflow are you using for 2.79b I just rolled back to 2.0 and it now shows some edge lines but nothing still happens.

I would have preferred to post this as a comment but I need to have 50 reputation to do that.
As has been stated, the authors have stated that a 2.80 version will be produced and that work would begin once the API had stabilised. I would assume from that the at least initial work has therefore begun as the API was declared as stable when the public beta launched.
The point I wanted to contribute however was a tip on working between versions. I have found a number of issues with the import/export addons, which again translate back to the current beta status and the fact that most import/export is considered as an addon to the core functionality and thus lower priority.
What has worked really well for me so far is (surprisingly) copy/paste. It will no doubt depend a lot on the structure of your objects but in my case I have been able to select the objects I need to retopo while in 2.8, ctrl-C to copy them, then tab over to Blender 2.79b and paste them in (ctrl-V). Occasionally I find the copy/paste buffer is not picked up, but reselecting and repeating fixes that so I suspect human frailty more than bugs, is responsible for that.
I hope this helps. Perhaps a Mod might copy this up to a comment on Craig's response as it's not really adding anything new to his answer but simply offering some further hints for Craig's suggested workflow.


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How to remove this distinct line in my texture?
I know it is something to do with uv unwrapping but I am unsure as how to fix it. Any help?

The problem was there was two strips of faces going through the big one that I used to extrude the chair leg so I deleted the strips and big face then filled with f and that fixed the problem.

I'm not very good at texturing myself, but it's hard to tell what's wrong without seeing a picture of the unwrap.
That said, if there are texture lines in the middle of your object, you likely a) have a UV island or extra mesh face(s) in the middle of your table surface, or b) a non-tileable texture.
a) This could be because you've accidentally created an additional mesh face in the middle  of your table, or you've somehow double-mapped the texture to the face(s) in the middle.
 - go to Edit mode (tab), then wireframe viewport mode (z), then Face select mode (3)
 -  one at a time, select each face around the discontinuity, them move them out of place (g)
     - you should see the surrounding mesh stretch to the face location, Escape to cancel, go on to the next one
     - if you move a face out of place and there's still a face in the same place, you have a duplicated mesh. Escape to cancel
       - you can probably select all faces (a) and then go to Vertex > Remove Duplicates. Or just delete the excess vertices.

if the mesh is fine, then there's an issue with your texture or unwrap

So, how big is the texture?
If it is big enough to completely cover the unwrap island of the table surface without resizing, that's great.
Otherwise, you MUST have a texture which is tileable or else you have to scale up the texture/scale down the UVs (same effect).
I.e. a texture is tilieable if each side visually matches up with the opposite side - think wallpaper. (Again, can't tell what the texture is like without the unwrap view).
If the texture is bigger than the unwrapped table meshes, you can shrink it down if you want, but not if it's smaller, without some loss in quality. Obviously better if the texture and islands are not resized at all. It's a bit difficult to tell how it will look without doing it.
If the texture is tileable or it's at least as big as the UVs then maybe you have duplicate UV faces attached to the same mesh face. I'm not sure if this is possible though. Try selecting each face in the 3d view and seeing what UVs are selected. There may be multiple UV faces that get highlighted if this is the case. But again, not sure if this is even possible.

The "line" looks to me to be a narrow strip of faces that is not attached contiguously to the surrounding mesh, i.e. the wrong texture is applied to the faces. It lines up with the table legs. I'm going to guess that you split the table top in line with the legs and extruded them from there. You probably accidentally created an extra strip and assigned the wrong texture.

It turns out I fixed the problem an hour later by deleting those faces and filling it with just  one face but thanks for your in depth uv guide! I will be coming back to this if I have anymore problems lol.


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When i click to do stuff with retopoflow nothing happens cursor just moves around?
Thanks for your time and don't mind my poorly made rock.

Never mind I had to press control while clicking for results.


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Flip animation along an axis (Mirror animation)
Good day!
I created an animation of hitting a punching bag with my right hand (skeleton - humanoid), the question arose: how to reflect the animation (along the X axis) so that now there is a blow with the left hand?
I tried:

Created an EMPTI element in the center (0,0,0), made it the parent of the rig and applied a scale of -1 on the X-axis.
This option will not work because the animation and SKELETON will be reflected (bones will also be mirrored)!
I've tried copying frames (Ctrl+C) and pasting them by pressing "Ctrl+Shift + V".
In this case, the animation goes in reverse order.
The trolls wrote that in the liner you can click on the object and choose to mirror along the X-axis ... it's not funny ...

Please, help!

When you say that the animation goes in reverse order when copy-pasting, is it going backwards? Or in the wrong direction. You can reverse the frames in the animation sequence if its going backwards to create a "forwards" action.

"Ctrl+Shift + V" - This action makes the animation in reverse order, this is not the result that is needed to solve my problem)

Select all the bones involved in the animation of the right hand with your mouse over the graph editor press A to select all keyframes (make sure none are hidden), press W or right click and choose copy.
Select all bones from the left hand, make sure they have an f-curve for the selected channels (i.e. insert one keyframe for each channel, loc, rot etc.), select a frame  where you can easily delete the new keyframes.
Go to frame 1 in your animation.
Pres RMB or W and choose paste flipped.

IDK how to make the symbol for RMB or a key on the keyboard.

I forgot to mention: I'm not a simple animation, there are movements not only of the arms, but also of the legs and torso ... Is there a universal solution to this problem?

have you tried it? if you follow the naming convention, it should work with as many bones as you want


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Armature moves mirrored objects
So I sculped a body out of several objects and half of it's mirrored. When I parent the armature to one of the objects, as I move the armature, it will move the object alongside it's mirrored part. How do I stop that?

https://www.youtube.com/watch?v=J2QutynfhiM
I think this might answer your question

apply the mirror?

apply the mirror


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Blender Path Deform Bone Contraint Deforms Mesh
I am making a tram model to follow a path, so the "cars" turn naturally. I found this tutorial on Youtube and I have followed it to a "T", but something has gone awry.
When I turn on the bone constraint "track to" to follow the triangle cube thing, the first bone completely distorts the mesh.
I have done it before, using the same copy of Blender 2.84 (the latest "official" release from Blender) and I cannot replicate results. I have no idea what is going on. Is it just Blender being Blender?
The video I am following.
https://www.youtube.com/watch?v=VXheGvyEz3A&t=1086s
I would ask the guy directly, but comments are turned off and no contact info available.
Here is link to my blend file.
https://www.dropbox.com/s/5ygb9u15ibomi3h/followpathdistort.blend?dl=0

There is another method for this kind of purpose, which is better than this one, given here by Batfinger. That said your problem is just that your vertices are influenced by other bones, if I select one of the 4 back face vertices, here is what I see (by the way, Bone is probably your root bone, you haven't disabled its Deform option):

So simply click on the X button to remove these vertex groups, or use the Weight Paint Subtract brush.

Thanks for your reply.
I tried what you said, but it did not seem to change anything on my end. Here are two files where it was working. I assure you, I followed that vid the same as with the new files. With these files I did not do any messing with vertices or weight paint.
https://www.dropbox.com/s/0uv7830w9acj3pn/followCurveWork.blend?dl=0
https://www.dropbox.com/s/1x7c87qdazt6dzd/sara1.blend?dl=0

did you remove all vertex groups except Bone.001 on the 4 vertices? It works fine here

OK, that is where I goofed. All work now. Thanks again.
I must have added an object or parented wrong.
I will try other method explained above tomorrow.

you could also have done it with weight painting, select the armature, then the mesh, then switch to weight paint mode, and select the bones one after another, don't forget to select the root bone or simply deactivate its Deform option

the advantage of the other option is that if you ever extend the curve it won't move the train, it will stay where it is currently, it may be useful


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how to render an image without effect of scene world
I am new to 3d and blender. My question is how can I get an image rendered as on the left side of the image. I can see the Scene World is making the difference. Is there a way to render the image without the effect of the scene world?
Thanks in advance.

I don't really understand your question, if the image on the left is the one you want and not the one you want to avoid, the way to render a scene with those "world" reflections is by adding an HDRI as the surface input in the "World Properties" tab on the lower right.

This is confusing. You have the result you want on the left, but you are still asking how to.

@ChaudhryYousuf, but when I render the image, Render->Render Image, it is producing an image that is on the right side.

Can you share your .blend file?

What happens when you check/uncheck the Scene World option, is that blender toggles between the lighting you have set up yourself, and a pre-built (and hidden) HDRI that provides lighting and reflections (as seen by default in the Shading Tab)
So, to get the same look for your render , what you are looking for is the effect of HDRI lighting. Go to the world section of your shading tab and add and Environment Texture (not an Image Texture). You can use any HDRI you want, but the one that is being used in your example is in your blender folder at ....2.92/datafiles/studiolights/world and the image is forest.exr (there are others there too). You can also find many free ones online - one of the most popular places is HDRI Haven (https://hdrihaven.com/hdris/).
If you want the lighting and reflection influence but don't want the image as your "background", you can mix the Environment Texture with another Background (I used the default) using the Is Camera Ray output of a light Path node as a Mix Factor (as shown below):

How to use 2.8's default HDRi's in renders?

@Chirstopher Bennett, aha, I see. color in world property needed an hdri image rather than a solid color. It also seems Vector is also playing a part in the final rendering. Thanks very much for your detailed explanation.


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Hilariously LOW fps!
I was working on a cloth simulation in Blender v.2.83.4 LTS. I made all the assets ready and also had modified them properly. Then, at the time I started the playback, I noticed a hilarious fps roaming around 1 and 2 frames/sec. I had never seen this low fps in Blender.
My Laptop specs:
MODEL- Dell Inspiron 15 3567
RAM- 4 GB total. 3.88 GB usable
GPU- 1 GB usable
Processor- Intel Core i3 7th Gen
Yes I know that the specs are not so high, but I had done even more complex simulations and animations with ease in atleast 20fps.
Someone please help me out.

Did you bake the cloth simulation?

i also have similar specs with 8th gen i 5 , but it happens rarely when i have heavy stuff like " Colth Simulations'


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How to make rigged fingers follow a rotating crank handle's bone
So I have a simple musical box rigged and animated rotating its crank handle.
I have also a rigged hand posed to hold the crank handle of the box.
I want the rigged hand to follow the rotating crank handle so that it looks as if the hand is actually rotating the handle.
I tried probably all of the constraints but none of them seem to solve my problem.
I have also a control bone on the hand rig that I tried putting constraints with the bone3 of the musical box, such as copy location, tracked to, locked track and so on... But didn't work
Any suggestions ?

have you tried to give a Child Of constraint to the hand bone with the crank as Target?


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UV unwrapping Problem
I need to UV unwrapping this model and tried many ways to do this but still think should be a better way to do that. any help is appreciated.
the blend file is attached.

Hello, why do you think it's not good? It's seems good, maybe scale it a bit on the X axis to get a more square grid? Also it depends on what you want to do with the UV map

Hi. with the help of the Ribbit12 I fixed my topology :) I am going to texture this model and the UV should be correct for that.

HOW TO UNWRAP
STEP 1
add a seam in the middle of your mesh

and it should unwrap like this

STEP 2

You might notice that your Uvs are still distorted and rotated to fix this you will need to download a Uv Square addon from online(free of cost) link is given below.
UV SQUARE ADDON LINK HERE
Go to download code > press download file
Then open blender preferences add ons menu and press install

Then select the zip file that you downloaded from the given link and press install add-on
Now search UV square addon in the addon menu and enable it

STEP 3
press A to select your mesh in edit mode and select both of your UV islands by pressing A on your keypad . Now open the menu by pressing N and then go to the UV squares tab in your menu and press the options grid by shape and Tada! your Uvs are beautifully clean and straight.
IT SHOULD APPEAR LIKE THIS

HOPE THIS HELPED AND WORKED

you are the best bro. I am so appreciative of you. Thanks a lot :)

Your welcome really happy to help you

smt I took a look at your project file, found out that your mesh`s geometry is terrible. There are a lot of overlapping edges because of the solidify and subdivision surface modifier. So I think it's best if you add extra edges or subdivisions in the hard areas and scale it and avoiding the subdivision surface modifier as it subdivides areas where there are already a lot of edges and overlaps. Last but least you definitely need to add seams.
REMEMBER YOU CAN ALWAYS GO AHEAD AND ADD EXTRA EDGE LOOPS MANUALLY BY YOURSELF AND SCALING IT TO SUBDIVIDE RIGID AREAS INSTEAD OF SUBDIVISION SURFACE MODIFIER.

I JUST MOVED AN EDGE AND THE MESH GOES CRAZY THESE ARE SIGNS OF BAD GEOMETRY
*SM= subdivision modifier
An easy way to clean up your geometry and unnecessary vertices is by pressing A to select your whole mesh in edit mode and press M and merge by distance.

Thank yo so much. your answer was so helpful and I am going to fix my topology. I still have problem with UV. I added the seems like you did but did not work. can you upload your unwrapped model blend file please ?

I will send a clear explained answer how to uv unwrap really clean in a few minutes

Thanks you bro

happy to help! Your answer is sent

hi! smt I have made aome changes to your mesh(only the top face) and I have unwrapped it more better by adding some more seams.I could have explained the process but since you asked the file I am just going to send the file to you

FILE:     https://blend-exchange.com/b/W3eWb05B                      The unwrap is not brilliant but it will do the trick

NOTE: the end result of the method that you will have followed in here in the solution I have given and the model in the given file are different.


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Dark areas in glass
I have been following along with Blender Guru's Donut tutorial. I reached the end of Level 3 Part 4, but I seem to have a persistent problem - the shadows on my cup and plate are way too dark. I initially thought it was because of my camera angle/light placement, then I thought it was a problem with the liquid but after hiding it from view, I see that it was neither.
Here's what I have done:

restarted the whole cup process, followed along with the same videos to ensure I didn't miss anything.
changed glossy and transmission bounces to 128, 64 and rendered with no changes.
deleted the glass material and tried setting it up again.
moved my scene light far away and changed its power/radius.
checked that my plate and cup are not intersecting.

What I have figured out is that when I elevate my glass and plate above the plane, the transparency of the materials seems fine, and matches BG's results. But when I set it nearer to the plane, it darkens.

So I'm guessing it must be something to do with the plane, but changing material of the plane, and setting it back to no-material also yields the same results.
Note: in my blend file the BG camera and BG light are what I made to set the scene to mimic Blender Guru's lighting/camera angle to make sure it wasn't my composition giving me skewed results.
Thanks in advance <3

The other thing I notice from the pictures is that you've got highlights on the rim of the saucer and the bottom of the inside of the curve of the handle, while he does not, and this difference is in both of your renders.

@jwrush Do you think this could point to somewhere my modeling may have gone wrong? I went back to my blend file and made sure that the edge loop at the rim of the saucer and the handle aren't skewed in some way, but couldn't see any glaring messups.
I also went back to the youtube video and his also seems to have the same highlights, just a bit harder to spot because of the pink plane, I think.

Playing around with your blend file, I can change the color very close to his pink and I'm still getting them more vividly than in the screen shot.   I also don't think it's a modeling problem, because I can distort the cup drastically and the shadows don't really change.  My best guess is that it's either lighting, the glass material, or render settings (all of which I know you've checked a ton, and all of which look reasonable to me, though I've never done the tutorial)

You've limited the Max Bounces of the light to 6. The default value is 12. Fewer bounces mean faster render times (1:01 vs 1:12), but more noise and darker (glass) materials. Reset the value to 12 and your cup will look much brighter.
In your provided file the Denoising Data was not generated. You need to enable it in the View Layer Properties tab and connect the nodes in the compositor.

This was it, thank you so much! I guess I must've changed it at some point and I glossed over it because having 6 min light bounces under advanced and and 6 max bounces  in the light paths didn't stand out as a problem. I did have denoising enabled before but I even tried turning it off to see if that was the cause somehow. Thank you again!


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Weird Face Snap During Retopology
I have apply decimate modifiers on a sculpt and trying to retopology, but i have experienced some weird face snapping while i want to move the vertex as shown in the gif, may i know what may be the problem?

Besides, may i know what is the point for applying decimate modifier, or even use some retopology tool like instant meshes before we retopology by ourselves? Because we are going to retopology it anyway so why do we take extra steps to reduce the amount of faces first?
Thank You so much for helping.

"[What is the point of a decimation, if before we retopology by ourselves.]" Good question, who said that that was a good idea? Any Sources?

@moonboots
Are you referring to this snapping setting?
https://imgur.com/MgD4TQV.jpg

yes it looks good

@moonboots yea because i was following a tutorial, but i could not proceed because of the vertex snapping problem. Any possible solution for it?

@Leander
I was watching this video
https://www.youtube.com/watch?v=OuFwUaS8y1I&t=287s
At 1:18 he mentions that he decimated the mesh, but i just wondering why he does that.

He doesn't explain it and you should decimate it is definitely not always true. If you have no performance problem with your high poly model and are planning on doing a full manual retopology, there is no need for simplification.

Can you make sure your snapping settings look like this.

@Che Xuian yes sorry, not vertex, face is the right setting

Yea i changed the setting like leander shows, but it still does not work. Tried to redo it on a new project but also does not work.

Hi, i found out that if i move to other angles and try for few times, the vertex can be moved without this weird snapping, so i assume this is not a setting problem. Thanks for trying to help, may you response to my another post related to texture painting if possible? Highly appreciate the help from you :D https://blender.stackexchange.com/questions/176586/what-details-should-show-in-sculpting


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Baking normal from high poly to low poly
I sculpted a high res model, and retopologized a low res model. I want to bake the normal from the high res to the low res, so i use smart UV project to unwrap the high res and the retopologized low res > placed them at the same position > created an image texture > ticked selected to active and then bake. After baking, i plug the normal into the principled BSDF's normal input, but the result seems weird.
Firstly, is the my flow correct? I am following the steps from the video :
https://www.youtube.com/watch?v=0r-cGjVKvGw&t=5s
But since it is a character, i not sure is the same flow can be applied.
Besides, the normal map is having some parts shows as green and orange. I tried to increase the ray distance but it does not work also. May i know any possible fixes?

Thank you so much for helping :D

On the Image Texture the Color Space must be Non-Color instead of sRGB. I don't know why it is greyed out (may be you plugged it in before baking). Try to save the normal map then load it again.

Yea i also not sure why, but i try to create a new image texture, set it to non color and bake it again then it works abit better. But may i know is it a correct way to directly baked a triangulated high res model into a low retopologized mesh?

Yes, it's correct. The topolgy doesn't count, just the shape.


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Shader Editor does not reflect on action
I was trying to adjust the nodes for object and world, but the shader editor is not responding as shown in the gif. May i know what caused this problem and how could i fix it?

Thank You so much for helping.

This is not how background textures work. You need to have an HDRi image (hdrihaven.com) and you need to hook it up to the output through a background image node, not a Principled BSDF. The easiest way to do this is by just opening it on the right side in your world properties, where it says "open". You might want to delete your broken node setup first.

yea thanks for trying to help. I know i should plug an environment texture on the world node setup, but the problem is i cant navigate to there, since it is broken like the gif shows. It is not linking with any of the object i clicked.

You have "pinned" the object texture shader editor window. Just click on the pin icon on the middle of the screen next to where you change the name of your materials. For your information this is useful when you want to tweak several materials at a time because by default, the shader editor window shows the material of the select object

Thanks :D I cant believe i wasted 2 hours for this, but i did learned a lesson from it lol. May i know is there any short cut key to enable it? I dont think i did it intentionally.


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Difference between bump map and normal map

Does normal map contains height information? Because it stores x,y,z axis information, but is the z axis equals to height information? But some comments I saw said that normal map does not contain height information, then what the z axis is representing?
Why does bump map is ‘directionless’? From my perspective, they store the height information in black and white. With that information, how does the direction of the bumps cannot be retrieved? I tried to create a simple bump map example to show what I am trying to ask. The below bump map only has a white rectangle, so the white will be pulled outwards and the black will be push downwards. But isn’t that we can already know the direction by the white and black data? Such as the direction that I marked with green arrows, which shows the 5 direction of the faces for the rectangle (1 top face and 4 side faces).

Many people claims that normal map and bump map are nearly same, but the below normal map and bump map has quite a high amount of differences, so how are they nearly the same when there could be so much differences between them?

I know the difference between bump map and normal map are probably asked and answered by many times, but I don’t really find any answers that could answer the questions that I have asked above. I sincerely feel sorry if there are repetitive question asked.
Below are some articles and sites I have searched, but I feel like there are conflicts between them so I wanted to make the concept clear.
https://www.pluralsight.com/blog/film-games/bump-normal-and-displacement-maps
https://forums.cgsociety.org/t/normal-vs-bump-always-better-to-use-normal/1410917/52
https://blender.stackexchange.com/questions/ask
Thank You So Much For Helping

Perhaps related: https://blender.stackexchange.com/a/176717/

Related but not thoroughly explained Bump Maps vs Normal Maps

You won't have any height info with normal maps because what normal maps record is the inclination of a normal compared to the face that bakes... for example if the face that bakes is fully frontal to the normal of the face to bake, it will stay blue, whatever the height of the face

This has nothing to do with blender, but could be useful anyway.
The normal map contains pixels with vectors. Each pixel has a vector, where is that pixel pointing. In the standard light blue purple color, it is pointing straight out from the surface. As the color changes, it points in different directions.
A heigh map (or bump map) has a height value stored as a value between black (lowest) and white (highest).
The bump maps in your post doesn't look like it will produce roof tiles when projected on a flat surface.
They describe about the same information, in different ways.
Looking at a single pixel in a normal map, it is impossible to say what height it is. Just the way the surface is tilted (direction and amount). But if you look at more pixels surrounding it, you can build up a relative height. If you stand on a slope, you can see that, up the slope, the ground is higher.
Looking at a single pixel in a height map, it is impossible to say what slope it is. But you know exactly how high you are. But by looking at your neighbours, you can work out a slope.
To work with a normal map in a material in blender, you have to run it through a Normal map node. This also have a strength value, to determine the scale of the bumps.
EDIT:
To me it looks like your bump map isn't meant to be put on a flat plane. It looks like baked normals for a lowpoly model of roof tiles. I don't know where you got these maps.
The normal map you have, that will give roof tiles when mapped onto a flat plane. Not very good ones if you get close. But from a distance, it will work.
Here is an image I made, showing the difference. Normal map on the left.

This is a great answer, learned something new here :).

Hi, thanks for helping. So normal map contains slope information, and we can get height information indirectly with the help of slope. Bump map contains height information, but we can also get the slope information because it ranges between full black and full white.
But if they both can get the height + slope information, then why are the normal map and bump map that i attached in the post shows totally different information?

@CheXuian I updated my answer

@Gunslinger Hi, thanks for replying. The roof texture are gotten from texturehaven. Sorry to say that i still can't really have a very straight concept on the difference between normal map and bump map. My main concern is still why both of these maps will produce height & direction information (either directly or indirectly), while they can look so different? Thank You so much.

I think you should forget about how they look at first, and first focus on what they represent. A normal is a vector that indicates the direction in 3d space of something. In rendering, you use this e.g. to calculate the direction light bounces off of a surface. In the normal map, the length of the vector is always 1 (well that's how it works in other 3d graphics calculations, maybe it's more nuanced in Blender). A height map indicates for each pixel how much it 'sticks out' relative to the surface the height map is applied to, and in the direction of the surface normal.

So why do they look so different - because they represent different things, and in different ways. A normal map has, for each pixel, a vector of dimension 3 (i.e. 3 elements) that together form a direction in 3d space. A height map has a height offset from the reference, i.e. a single value (so that's why one is a color bitmap, 3 values per pixel, and the other is b/w - one value per pixel). (if you're not sure about what exactly a 'vector' is, there is a lot of introductory linear algebra material online that will explain the basics)

(you really only need to read the first chapter of most undergrad level linear algebra books).  Once you really understand this, and you start looking at the bitmaps you supplied, and start reasoning through for a few pixels what they mean, you'll understand the relationship between normal and height maps.

Alright i guess i need more time to digest this, thank you guys :D


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how do I seperate hair texture from regular texture
I have a "Keentools FaceBuilder" head going with my face texture on it. I also have a simple hair particle system for my (scraggly) beard (picture 1). I have a simple "Principled BSDF" shader (For my face texture) and a "Principled Hair BSDF" shader (for my hair) mixed with a "Mix Shader" node and a "Hair Info" node plugged into the factor of the "Mix Shader" with the "Is Strand" as the output (picture 2). The result is to completely black out my face and only have the hair texture (picture 3). Is this the right way to split the hair and regular textures, or am I doing it completely wrong?

What you want are 2 materials:

one material for the skin (Image Texture and Principled BSDF)
and one for the hair. For Cycles, you can use the Principled Hair BSDF. It works only in Cycles and you have to switch to Cycles to be able to add the node. To have a fallback for Eevee and the Material Preview mode you can add another node setup in the same material that is used for Eevee only.

Just add another material slot for the head/emitter and create a material. After that, you can select it in the hair settings: Particle Properties > Render > Material
If you use Cycles make sure you have the settings for the Hair Shape correct (small values) else you will get very "fat" hair.


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How do I save a certain workspace as the default workspace (not default upon opening blender)
I want to save the default compositing workspace a certain way so that when I open the compositor, it's the setup I like. I've figured out how to save the interface for opening blender however, I'm wondering: how do I save the default interface to only that interface (basically the compositor won't be the default opening blender scene)

Any changes you make to any of the workspaces can be saved as part of your Startup File.
Here's my Compositing screen, I also enabled the denoising data passes so I could denoise renders by default.

Just open a new file, make any changes, and go to this menu.  Whatever workspace you're currently in will be the one Blender opens to.


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How to export textured mask as an image
I have a simple node setup (picture 1) that is creating a mask on my 3d object (picture 2) and I want to be able to export this as an image to edit. Is this a possibility? When I go to the UV editor, the image isn't there for me to view/save.

Does this answer your question? - https://blender.stackexchange.com/questions/133044/how-can-i-create-a-mask-by-baking


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Fluid sim effector not working correctly
I have a simple fluid simulation set up and, I have an "effector" object that is supposed to be making the fluid collide with it.
The problem here is, I've set the effector strength "Surface Thickness" to 0.3 which normally is quite enough. But here (as you see encircled in yellow,) the fluid is passing right through it. So I can turn the "Surface Thickness" up a little bit and it works then except, then the FLIP particles ride obviously on top of the plane ([picture 2] which obviously doesn't work.) I've even tried to set the "Sampling Substeps" up a bit but to no avail. Why is my fluid sim doing this?

It appears that you found the solution?  Your blend file worked for me.  The Collision Effector surface thickness has to be at least 0.5 Thickness, which I have reported as a bug.  And I have no idea why the default Sampling Substeps is '0', when I find that is often insufficient.


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Textures black out after remesh?
I have photoscanned a fire hydrant and as all photoscanned objects are, its mesh is a total wreck. So I remeshed it using Quadriflow remesh. But after the remesh was complete, the new object was completely black (left object). I can't just unwrap the object because the textures are baked onto the image for the photoscan and are totally random (as seen on the right.) How do I apply the textures to my new object just like my old object?

Quadriflow remesh will remove any UVs you have, one solution is to use Data Transfer modifier on the remeshed version, to transfer UVs from the photoscan to the remeshed version, use settings in the image below, you should also place both meshes in the same location, and preferably hide the photoscan
Another solution is to use the Remesh Modifier instead of quadriflow at the cost of low topology quality.

Thanks! It worked mostly but all the textures were split apart at the seams. What do I do to fix this?

Not sure about this one, maybe we could experiment on the blend file


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New Blend File has A LOT of orphan data
Everytime i start a new blend file, i have orphan data.  3 materials that won't go away 99 meshes, and 99 objects.
Tried purging them and resaving the startup default. But they come back everytime.
How to i clean these once and for all.
On the latest build 2.93.
Thank you
Gary

There is File -> Defaults -> Load Factory Settings, but this is what usually works for me.

Purge data.
Save the file and close Blender.
Reopen the file you just saved.
Immediately save it and close Blender again.

Now the data blocks should be gone and you can open it and set it as your default startup file.
If there is still some data hanging around for some reason, you can switch your Outliner to the Blender File display mode and delete the data blocks manually.

Some things don't seem to be properly marked for deletion, it's never been clear to me why.

Tried this...everytime time the objects and materials reappear. Its always 99 object, 99 meshes, and 2 materials.

That is weird.  My initial thought is that your OS isn't allowing write access to the file for some reason?  (Assuming Windows) You can find your default file in %appdata%, might be worth looking at it and seeing if anything funky is going on in Windows.

Its writing correctly. Save anything i do the a new startup file. But always adds the objects/meshes and materials. Tried factory reset....the were still there.


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How to render this
I downloaded an obj+mtl from Betanji (on the left image) and tried to render it on cycles (on the right image). What I supposed to do to get the same render as on the Betanji site??

Hello, you need to work on the materials and on the lights I guess, your question is probably a little bit too broad

I used a hdri as image texture for world light. And I thought that the mtl file control all the material things well (color, roughness, transparency...) but it does not even familiar with the showed image:( Anyway, thanks for your answer, Im trying to fix it;)

In addition to using an HDRI, the lighting for those kinds of scenes are usually done (in cycles) by placing a (relatively) large plane nearby at an angle and giving it an emission texture (to simulate studio "lamps"). From your image, it looks like all you have for lighting (besides the HDRI) is the default "point light", embedded in the center of your scene (between the bottle and the jar). I could be wrong, though - its hard to tell from the image. Also, make sure to connect the alpha outputs from your images with transparency to the alpha input of their respective Principled BSDF's (that could be responsible for the black blotches in your glass objects).

Thank you very much! You were right, the materials were unaccurate and nods were plugged badly, I also put up large area light which helped a lot. Thans again @christopher bennet and moonboots


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photorealistic glass bottle render
how can I achive this kind of material for glass? (photo attached). It looks like noise texture on very high scale, but when I try to set it, the bottle roughness is rising so high it losts the shiny glass material character. Thanks for your advice.

I would use something like this for the material - use the Noise texture as the basis for a Bump Node, and then use that as the Normal for the glass. I mixed it very heavily with white first (.998) otherwise, it looks too strong and unrealistic. You can also do this by adjusting the strength on the bump node, but I feel this gives more "fine" control. Lastly, use the Facing output of a Layer Weight node, to mix the inner "lighter color" with a more opaque outer "brownish". Don't forget to adjust the Blend Mode settings if you are using EEVEE (right side):

Why use an extra node to mix the Noise with white? The Bump node has a Strength value and a Distance value, I usually use Strength, in tutorials they often say use Distance to control the bump... anyway, simply decreasing the Strength to 0.08 with Distance = 1 gives the same result... or Strength = 1 and Distance set to 0.002 (there you even have a correlation to your mix factor: 1 - 0.998 = 0.002) also looks the same.

Old habit, I guess. Carried over from Substance Designer.


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How do I fix an imported model?

I downloaded this Zelda 3D model last night and imported it into Blender. This is the model I choose to import:
However when I imported the model I found an error in the model. There's large hole in the side of her waist, her left foot is inverted from the position of her body and both feet are sideways for some reason. I don't understand how fix the issue as I haven't used Blender to animate for anything before. Is it a rigging issue? Bone position? How do I fix this issue?

hello, you've already asked your question and it lacked clarity, it's the same thing here, so please edit your original question, give some details and if it's possible share your file here: https://pasteall.org/blend/

Hello and welcome. Please don't post the same question more than once. If your previous question was put on hold, address raised the issues by editing it so it can be reopened rather than post a new one, otherwise see What should I do if no one answers my question?


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Blender 2.8 Scripting for a simple button
i was trying script a button in 2.8 i stared withe the templates UI panel
but i wanted to place in the top bar which error out if i change the layout
is there any way to place the button in the top bar?

Pre or Append to the header.
With all panels and headers in blender you can append or prepend a draw method to them.

Test script prepends a splash screen button to topbar
import bpy

def draw(self, context):
    self.layout.operator("wm.splash")

bpy.types.TOPBAR_HT_upper_bar.prepend(draw)

To find the class to "leach" onto, with developer extras on, right click and view source. With the naming convention, TOPBAR pretty self explanatory, HT it's a header type. Hence using autocomplete in python console is a way to find contenders

thanks i'll try and see if it works


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Changing node structure during an animation
After doing some quick research on animating nodes, all i could find was that you can animate values, but changing the structure was not addressed. I would like to change the order that i composite the layers in since the view changes necessitating this a rearrangement of the node structure. I know i can render select parts of the animation separately and restructure the nodes before doing the next segment, but if i could get it to do that on it's own I could render it all at once while i'm at school or asleep instead of checking in every hour or so to doctor it.

You could create the two node setups you need. (the two versions) and use a Mix node to mix from one setup to the other. You can keyframe the factor to do that automatically.

Oh, so basically make all the structures i need and fade between each set as i need to?

Basically yes. There's probably a specific frame at which your rearrangement needs to take place. So you can keyframe from (e.g.) 0 to 1 from one frame to the next.

Actually no, a fade might be just what i need. I'm singling out a laser to add a glow effect to only the beam, and i switch the layering as the housing of the laser passes the beam, but the glow sudden disappears so a fade could doctor that. Thanks for the answer.

Great! Just another idea: you could also render the housing on a separate renderlayer and use that as a matte before the glow. That's probably the precisest way to achieve that.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


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particles come together to build text
So I am trying to create a cloud of particles that come together to make  text for a little end card for a school video project and I found a video that does basically the opposite effect.
I was wondering if there is a way to reverse that effect without literally reversing the frames. The only reason i can't do that is because i also have some dust specs floating around in the background using depth of field so i can't mask the text and composite or some other wizardry as far as i know.
Here is the link to the opposite of the effect i want: https://www.youtube.com/watch?v=Q93pE5jB1Uw&t=234s

You are looking for Keyed Particles. Here is the Blender Manual page on them. Google around and find a tutorial on them.

Thank you Scott, this looks like exactly what i need. Thanks for the help man.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


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Use tracking point to move a plane with an image on it,
I'm looking to track an object within a strip of frames in the video editor.
To clarify, I'm not trying to track an object and solve the camera motion. I'm looking to use a single tracking point to track the head of a character from a video and i would like to make a plane with an image on it follow that point.

watch for "Track, Match, Blend!" on YouTube...

The BF tutorial for that is called Track Match Blend - you can find copies on youtube.

I should have clarified when i made the post, i'm not looking to place objects into a video clip like one would usually use the tracking for, I'm looking to do something along the lines of tracking a persons head for example and layering another picture over the video.

Thank you cegaton, this is exactly what i was looking for.


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How to slow down an object following an animated path?
I was wondering on how to slow down the speed of an object following a path (that has been animated.) I'm trying to slow down how fast the UFO (with a particle system) goes along the bezier circle I've made, but I can't seem to find that option.

Never mind, found it! If you click the bezier curve (or circle in this case) and go to the Data tab, scroll down to see Path Animation, and increase the frames which decreases the speed.

With the path selected, in properties panel, in curve tab, Path animation section, you keyframed the Evaluation time.
In graph editor you can select the Evaluation time curve and scale it frame-wise with gx and enter any number you want:

Thanks for the tip, however when I select the path, it only has a red line that can't be edited, unlike yours which has a yellow editable line.

you keyframed the evaluation time too?

Parenting an object to a path keyframes and locks the evaluation time automatically. In graph editor, select evaluation time and look at its modifiers. Underneath "Expanded polynomial," activate "Additive." This should allow you to use keyframes to control the speed of the object on the path. You need not keyframe the frame count of the animation.


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How to change the thickness of grass hairs?
I'm trying to find a way to change the thickness of my grass hairs, but I can't seem to find them? In materials mode they seem thin and just fine, but when I render them...they come out like this:

You can set that in the particle system strand settings

I can't seem to find that in my Materials or Particles tab, I'm working in Cycles Render.

Properties Window > Particles > Cycles hair Settings > Thickness then Root, Tip, Scaling if you are using Cycles, hard to miss.

Mate i have a better idea for u, A way that I like to create Grass is using Planes, Not cylinders because they use way to many faces. The Goal in 3D art is to create as little faces as possible whilst still achieving a great Render. Try and create a narrow plane and scale it along the z-Axis then extrude it to make it look like a strand of Grass. Then duplicate it about 15 times moving them in different Locations to make it look like a Grass Blob. Add it to a Group. Then go to your Plane section and add a Vertex group. Go to weight paint and paint where you want the grass to appear. Then add Particle System/ Hair and click advanced. Scroll down to where it says group and click the object you added to a group. (The grass) There you can change the size and brownian to make it look like Grass.
And viola, you get an awesome scene that you can change.

This was a plane, and I didn't use a cylinder at all. But, I'll try your way.

The strands of Grass appear as Cylinders here.

he's probably using the "Path" render instead of "Object" or "Group"


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How do I model a cave with realistic textures that show dirt and imperfections in the floor and walls?
I modeled a cave by starting with a cube, subdividing it, increasing the size and flattening the bottom. It looks like this now:

Using dyntopo I made the walls and floors all scratched and scuffed up.

I separated the floor and all of the other vertices by placing them in separate vertex groups. I used a ground texture for the floor vertex group and a rocky texture for the other vertex group.

I was frustrated because it looked bad. I figured it would be more realistic if I used a color ramp to make the ground texture stick to the lower points of the bumpy floor, and the rocky texture stick to the higher points of the bumpy floor. To do this, I used a texture coordinate node, a separate xyz node, a color ramp node, and a mix shader.

This worked in the sense that the ground now had dirt on the bottom parts and rock on the top parts but it still looks terrible.

There are 2 obvious problem that I see with this scene. The first is that I think the dyntopo sculpt job looks really bad. Idk if there's a better tool or if I'm just doing it wrong. This is a wide shot of the cave after I finished sculpting.

Maybe I need to buy some good brushes?
The second problem is the fact that the textures look bad. The patchiness on the floor doesn't look right and the displacement isn't actually displacing the surfaces. Does anyone know how I can imporve this? Here is a link to the Blender file https://drive.google.com/file/d/1CL4QPdn1yh7KqTBDYCLes4zKB1ZRN8ak/view?usp=sharing.

Please do not use google drive links in your question. You can share your file at https://blend-exchange.com/

The node group that you're using has a setting for the displacement strength. It's set to 0. That's why there is no rendered displacement. Furthermore, the displacement requires geometry. It doesn't work very well together with DynTopo because if you use this feature the mesh will have a different density in certain areas. For the height map displacement, you want to have a uniform density. Better do a quad remesh and add a Subdivision Surface modifier if needed.


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No "Final" option under Physics Properties > Cache > Type
My question is pretty simple. In all the tutorials I've watched at some point the instructor says to set the option Physics Properties > Cache > Type to Final but my only options are Modular Replay and All.

Okay I think I figured out a work around. So I just need to break it into several steps.

Check checkbox Physics Properties > Fluid > Mesh
Set Physics Properties > Fluid > Cache > Type to Modular and check Is Resumable
In Physics Properties > Fluid > Settings select Bake Data (after this process runs the button then changes to say Free Data
AFTER STEP 4 - In Physics Properties > Fluid > Mesh select Bake Mesh (after this process runs the button then changes to say Free Mesh)


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Why the particle does not appear in cycle render mode?
I follow the youtube to make towel texure by using particle. However, the texture can work in eevee render but not in cycle render. What is the problem or what steps I miss? Hope you guys can teach me, thanks in advance!
Here is my file link

Adjust the Hair Shape, this works in only cycles, that's why the Eevee render different. https://docs.blender.org/manual/en/latest/physics/particles/hair/shape.html

Your hair is not showing because the strands are tiny. You set them to 0.002cm and a scale of 0.01, so they are virtually invisible.
Don't mix a shader with nothing, unless you are going for a stencil effect.
Use a hair shader if you want to render hair. Normal shaders can work, but there's a reason hair shaders exist.

Hope that helps.


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Why pressing F to join two vertices not work?
I press F to merge two vertices, but they only extend a bit (second photo below), not join together? Could you please help me out of this problem?

Link to my file

Moonboots already pointed the issue, so just extension - after you delete duplicated vertices you can connect ends of path also by Alt+C (Toggle Cyclic - Close/Open Loop) without need to select points. Also in this case if you would use this operator the issue will appear by it self :)

Actually, if I grab your top vertex and move it to the right...

here is what I have, which means you had some vertices overlapping:

In a bezier curve, a vertex can't be connected to more than 2 other vertices, so just delete these vertices and join again with F, or as pointed out by  vklidu, select all and AltC.


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Subdivision + Solidify + Bridge Edge Loop
I try to create a chair following the youtube tutorial. Could you guys tell me why the object seems like broken, not a smooth rectangle after I use solidify. Also, the same happen again when I use the modifier in order Solidify > Subdivision and then Bridge Edge Loop to connect two faces. Below images show the problems and the file link is also added Blender file. Appreciated if you can help me out of this trouble.

Your face orientation is causing this problem. To see face orientation you can check Face Orientation under Viewport Overlays tab. Blue is outside. Red is inside.

To solve this select your object and toggle to edit mode. Press a to select all. Then press Shift+n to Recalculate Outside. This fill flip normals that are inside-out. You can also select Mesh tab and from Normals select Recalculate Outside.


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OSL error whend rendering/previewing in Beta 3.5
Does anyone know why I get this error when trying to preview or render with Blender 3.5 Beta with OSL and light tree enabled?

OSL group data size (2296) is greater than the maximum supported with OPTIX (2048)

And nothing gets rendered. How do I increase that data size pool and make it work?

Is it practical to include the OSL script in your post?

Not sure what you mean. I'm just using stock 3.5 build from Blender website with "OSL" checkbox checked. Did not add any other scripts anywhere.

Sorry..  I thought, if you had OSL checked, it you would be to run OSL Shaders .  I'm not aware of another reason to do it, but am open to correction.

See maybe #104304 - OPTIX OSL Group size error - blender - Blender Projects

Under Render Settings uncheck Open Shading Language setting.


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Is there any way to mask out surface and leave reflection/shadow only?
I'm trying to create a composite image with bottles on a table and I need to have shadow/refraction/gloss of the bottle to be separate from the bottle itself. I tried Shadow Catcher pass, but it creates something messy and wrong, that doesn't look right when used with Multiply in Photoshop. Is there any way to mask out table surface in this case and just keep whatever shadow/gloss the bottle produces? Or create a pass that would have all of these combined or at least separate layers I could combine in PS?

If you mean that you want layers that separate out the rendered static part of the background from the object area that includes a rendered shadow (animation purposes?).... you could try using a Mask modifier on the non-shadow static surface and then reverse the mask for rendering that includes the shadow.  Define a vertex group that includes the shadow area for the Mask.

Not exactly, I want the pass to have just shadow/reflection only, I don't need table surface itself. Usually 3D software has "matte reflection" option, but I don't think Blender has anything like that.

There is an option for objects, when Cycles is the render engine being used, to use them as “shadow catchers.“ They will not be shown in the render except in reflections on other objects, and shadows will cast onto them. This option is in the Visibility panel in the Object tab in the Properties editor, with the object selected.

I'm looking to have a reflection catcher though, not just a shadow.


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Suddeny can't paint texture, object looks greyed out
I'm trying to paint a texture and all of a sudden the object in the viewport turned greyish or washed out and I can't paint on it at all. Meanwhile I can still paint in the flat 2D texture view no problem. Is there some mask turned on or something? Why does it look like this?

hello could you please share your file?

I solved it. "Paint Mask" button on top suddenly was enabled. Not sure if I hit some hotkey that does it accidentally, but I never actually clicked it.

Ok I figured it out. That tiny button "Paint mask" (2 squares on top next to "texture paint" drop down) was enabled. I DID NOT press it for sure and didn't click it. Absolutely not sure why it suddenly was enabled, but that was the culprit.


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Texturing problem looks like broken image
i am having a problem right now, i add some image for floor but when i was trying to rendering, i am taking this view. How can i fix this ?

You seem to have two identical shapes and polygons in exactly the same places. One set of polygons has the texture and the other doesn't. Double-check this by right-click selecting anything in that space. Then press M and 2 moving whatever was selected to Layer 2. Whatever geometry stays behind will tell you which object, textured or not, you selected.
X Delete what's not needed. If what you needed was moved to the second Layer, press 2 along the number row (not numpad) and Right-Click select it and press M and 1 to move it to the first layer.
Blender Render and Cycles do not play well with sheets of polygons in identical locations.


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How to match blender with AZERTY keyboard?
I people, I just downloaded Blender and begin watching tutorials but I don't find how to match my AZERTY keyboard with the app.. (I'm from Belgium)
Thank you in advance!

You could just enable another keyboard layout to switch to when using Blender.

If using Windows you can set it up so that using Windows + Spacebar will switch between an AZERTY and a QWERTY Keyboard. Windows icon > Settings > Time and Language > Language > Prefered languages > click on language to get the Options tab > Add a keyboard > Choose the Uniterd Kingdom QWERTY option. Done. Now whenever you use the Windows + Spacebar combination the keyboard layout will toggle between the 2 layouts. You can see the change in the Taskbar bottom right. This method has the inconvenience that also using the keyboard combination SHFT + ALT also switches keyboards!

Me and most French-speaking blenderians I know haven't had major issues using AZERTY layouts:
Most keys are available on AZERTY in the first place, and you end up customizing your keymap to your liking anyways.
And since the big keymaps purge back in v2.80, there are even less QWERTY-specific keys and more room to assign custom keys.
So unless you have a specific function that you miss (in which case you can easily remap it), it's not that big of a deal.

I've looked through blender's settings and I don't think it is possible to use a non-QWERTY keyboard (in the typical way). That being said, there might be a few workarounds:

Change a few of the shortcut keys (go to edit/preferences/keymap and change the keys)

Use the widgets for navigation instead of the keyboard shortcuts

These are the navigation widgets

Press 'F3' and search for the function (e.g. move, extrude, inset, etc.) instead of using the keyboard, then press 'enter' to use the function


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Find vertex projection of one object on the vertex normal of another object
I have the following setup:

There are two objects: o1 (normal object; centered at the origin, no rotation) and o2 (it's a lattice; centered on a face of o1, rotated to match the rotation of the face). I want to move the vertex A (belongs to o1) to the normal of the vertex B (belongs to o2), represented by C in the picture.
So my reasoning is the following (everything is calculated in global space):

Calculate v1 by subtracting A.coordinates - B.coordinates
Calculate v2 by subtracting B.normal - B.coordinate
Project: v3 = v1.project(v2)
C = B.coordinates + v3
Transform coordinates of C from global space to the local space of o1.

The Python code that I have so far:
A: mathutils.Vector = ... (lattice point) obtain A in local space ...
B: bmesh.types.BMVert = ... (object vertex) obtain B in local space ...

o1_mw = o1.matrix_world
o2_mw = o2.matrix_world

v1: mathutils.Vector = (o1_mw @ A) - (o2_mw @ B.co.xyz)
v2: mathutils.Vector = (o2_mw @ B.normal) - (o2_mw @ B.co.xyz)
v3: mathutils.Vector = v1.project(v2)

C: mathutils.Vector = o1_mw.inverted() @ ((o2_mw @ B.co.xyz) + v3)

And it gives me some weird skewed results. Any hints to what might be wrong or another way to do this??
Thanks


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Geometry Nodes - Controlling Direction of Displacement
I have a flat cube with some subdivisions that I ran a simple noise displacement node setup through. I'm not using a flat plane with no fill because I want to have the sides of the terrain "cube" visible in my final render. In my node setup, I have a vertex group masking my terrain such that the top faces of my terrain cube should be the only parts of my mesh that are displaced.
My problem is that despite the displacement working as expected, I am seeing that the mesh is trying to displace itself in the X and Y axes, and is stretching the vertices on the very edge of the cube outward:

To solve this, I think I need to restrict the displacement so it will only deform the mesh in the Z axis. I haven't found much on doing this, however.
Here is my displacement setup:

I'm not quite sure how to proceed with restricting displacement in the Z axis. Any advice would be appreciated.

Would you like to use an existing mesh, or would you also be happy with a solution in which the entire geometry is created in geometry nodes?

Either option is fine, as long as the setup can be applied to both the same way. I'm not particular, but geometry nodes can get confusing for me.

I have provided you with both solutions in the answer below. Let me know if you have any questions.

To displace only the upper points of a mesh, you would have to select them correctly.
The node Compare, with which you can compare the normals of the faces, for example, helps you to do this. If you compare the dot product of the normals with $(0,0,1)$, you will get the faces pointing upwards as the selection. You then evaluate this selection with Evaluate on Domain in the face domain so that the node Set Position receives the associated points as a selection.
Something like this:

Of course, you can also build the entire mesh with geometry nodes, which makes things a little more flexible:

The Extrude Mesh node helps here, as it also provides you with the upper faces as a selection.


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Driver for controlling the splaying of finger bones using the Z scale of a controller bone
I have a pretty simple hand rig with only 3 fingers, and I want a controller bone to drive the local X rotation of the entire finger so that an increase in the Z scale of the controller bone increases the X rotation of the finger bone toward the center of the hand,and vice versa. I was able to achieve this for only one of the finger bones using a driver for the X rotation with the expression: var -1. However, this only works for one bone in terms of deforming in the way you would expect the fingers to splay naturally. When copying the driver to another finger bone, I want the X rotation to be mirrored from the working bone. For example, when I decrease the scale of my controller and end up with an X rotation value of -.3 for my one working finger bone, I want the opposite finger bone to have a mirrored value of .3. I can't seem to fix my expression in a way that achieves this.
Screenshots for more clarity:

Overall Rig

Driver Settings
In short, I want the not working bone to mirror the X rotation of the working bone. Simply changing the expression to var + 1 doesn't really work here. Any suggestions would be appreciated.

If you want to drive rotation, I wouldn't recommend using quaternion transforms.  Try an Euler (I usually prefer YXZ or YZX for bones.)  Changing the Z component of a quaternion is not necessarily doing anything to rotate the bone-- it depends on the other components as well.

If want you want is to "invert" the positive/negative value, I think you should use *-1 instead of -1.
But also, you shouldn't have fingers with different axis orientations to begin with, and the common standard for axes usage in fingers and limbs in general is:

X axis : fold
Y axis : twist
Z axis : splay

I highly suggest you at least make your bones' axis consistent with themselves, and even follow the standard so that other people using your rig and symmetry tools can work properly.
You can enable your armature's axes display under Properties Editor > Armature data tab > Viewport Display panel:

And you can change a selected bone's roll in Edit Mode using the Recalculate Roll menu with ⇧ ShiftN, any option you select will align the bones' +Z axes to what you chose. In my example gif it uses Global +Z.

Thanks so much! This was really helpful.


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Duo-Chrome Style Shaders
I've been attempting to create a material that mimics the effect you see in some cosmetics that are labeled "duo chrome" or "color changing", where you would have one base color that reflects a different color based on lighting conditions.
Some examples:

I've tried mimicking this effect using layer weight or Fresnel, but I'm not really satisfied with the results:

Here is my node setup:

I'm trying to get both the color shifting effect in the base color and the highlight color, but I'm kind of stumped. Any suggestions are welcome.

https://blender.stackexchange.com/questions/1605/iridescence-in-cycles https://blender.stackexchange.com/questions/82705/physical-iridescence-in-cycles https://blender.stackexchange.com/questions/50961/how-to-create-iridescent-glossy-tile-material https://blender.stackexchange.com/questions/99251/cycles-material-a-kind-of-glitter https://blender.stackexchange.com/questions/35815/how-would-you-create-a-cd-material-in-cycles/35817#35817


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World Shader Principled Volume Node Issues
I'm attempting to set up an underwater scene in Cycles by using the world shaders. My node setup isn't very complicated, it's just a principled volume node with the usual background node.The problem is that any density value above 0 completely blackens the whole scene. I want my scene to have an atmospheric look but still allows light to pass through.
This is the scene with density set to 0:

And this is the scene with .001 density:

I'm not sure what the issue is. I have a pretty strong sun light source in the scene, and this has never been a problem for me before. Any advice would be appreciated.

Hi. Please use a title that matches the content of the question. It should be descriptive but succinct, unique and identifying, summarizing the issue so that anyone searching for a similar problem is likely to find it. Remove anything superfluous, avoid using words like "this", "help with", "issue" or "question about", instead describe what "it" is. Remember, your title is the first thing potential visitors see, answers you get depend heavily on how insightful it is. See What is the problem of asking “How do I do this?"

It's probably a duplicate of https://blender.stackexchange.com/questions/78446/sun-lamp-and-volumetrics-in-blender-cycles


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UV Layout Does Not Match Image Texture Files
I have .fbx meshes exported from 3Ds Max. These meshes were originally extracted from Umodel (Unreal package file [.upk])
There are 3 separate texture files for this mesh

but the UV layout is just 1 (it looks like all 3 UV layouts were placed side by side, combined to 1)

I was able to manually fix the issue by combining all three image textures following the mesh's UV layout

but I'm wondering if there's an easy or automated way to do the following in Blender:

Separate the combined UV layout.
That way, I can have 3 UV layouts for 3 image textures.

OR

Combine all 3 image files into 1 without having to manually do it using an image editor. Maybe a node or material setup.

You can adjust each part to match the textures, separate them by material, and then you can create a new UV map with a single texture to bake to.

Looks like the model was made using UDIM which enables having the uv sets tiled like that. Blender is supposed to get UDIM support eventually, but isn't able yet.


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Align 3D cursor to face in python
I'm making a small operator that aligns the 3D cursor to the selected face normal.
I have the following code:
fnormal = obj.matrix_world @ selected_faces[0].normal
bpy.context.scene.cursor.rotation_mode = 'XYZ'
bpy.context.scene.cursor.rotation_euler = fnormal.to_track_quat('Z', 'X').to_euler()

This mostly works. The cursor gets aligned with the face normal like expected but the other axes are not aligned with the face.
When comparing with the "normal" transform orientation, its easier to see what I mean:

How should I change the code so that the 3D cursor would align with the face the same way as the "normal" transform orientation works?

Change 3D cursor Rotation
import bpy

# Select a face in edit mode first...

# change cursor rotation. First create an orientation and get the matrix, and finally delete it.
scene = bpy.context.scene

bpy.ops.transform.create_orientation(use=False)
slot = scene.transform_orientation_slots[0]

def get_orientation_list(slot):
    try: slot.type = ""
    except Exception as inst:
        s = str(inst)
        s = s[50:]
        return eval(s)

slots = get_orientation_list(slot)

old_type = slot.type
slot.type = slots[-1]

mat4x4 = slot.custom_orientation.matrix.to_4x4()
loc, rot, sca = mat4x4.decompose()
print(loc)
print(rot)

cursor = scene.cursor
old_mode = cursor.rotation_mode
cursor.rotation_mode = 'QUATERNION'
scene.cursor.rotation_quaternion = rot

cursor.rotation_mode = old_mode

bpy.ops.transform.delete_orientation()
slot.type = old_type
# change cursor rotation END

Do you happen to know where I could find the source code for the bpy.ops.transform.create_orientation operator? I would like to learn more about the math behind it. I tried searching on the Blender github but did not find it.

https://github.com/blender/blender/blob/master/source/blender/editors/transform/transform_orientations.c#L516


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I have some weird shading issues
I'm kinda new in blender so I'm trying to improove by making some low poly characters. But as you can see, I've got some weird shading issues. I have no clue how to fix this. And before you suggest me changing lighning or so - I want it to look cartoonish.
Any suggestions?

You could try selcting the whole mesh in edit mode (with "a") and then shift+N. That fixes the normals in some cases. I had about the same issue: https://blender.stackexchange.com/questions/131997/how-to-include-vertices-to-subdivision-modifier

Or use Ctrl+N if you are using Blender 2.79, Shift+N is shortcut for blender 2.8

It works! Thanks a lot. I wish i could give you thumbs up or so.


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Any idea why my model is getting squished?
It does this when i parent it to the bones with auto weights
or envelope
Before

After

your bones have weird proportions, perhaps select them all in Pose mode and press alt S

https://blender.stackexchange.com/questions/27434/armature-deformations-squishing-solid-objects and https://blender.stackexchange.com/questions/74072/parenting-mesh-with-armature-deformation-problem/74129#74129

turns out the bone constraint pole angle was messed up set it to zero and fixed it. Thank you!


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Cycles Gradient between two materials
How do i create gradient between two materials in one mesh? (second screenchot was edited in PS)

https://blender.stackexchange.com/questions/10453/how-can-you-smooth-the-edge-between-two-materials/10455#10455

Except those questions and answers didn't have anything to do with vertex paint. I hope that the solution I provided gives some use in that direction.

I think the title needs to be edited to add 'using Vertex Paint" that way it is more specific to the situation presented in the screen shots. That, and I can't figure out the best way to point them to my answer here except to replicate it again.

Here is one option to use the Vertex Paint Blur tool on the border between the white color vertex and the black color vertex. I paint the center area white in vertex paint mode, and then invert and set paint to black (in the header, go to Paint> Set Vertex Color and this will act like a fill). I used Face Select masking to do this without overriding the center white area.

I then switch tools to the Blur tool and blur the area around the white spot so that it cause a gray area. To deepen it, I subdivide once to force the vertex paint to blend across the changes. I then use this vertex color in the Attribute node (named Col by default) as a factor to mix between a diffuse black shader and a blue emission shader.


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Rigged character : Curves hairs (converted to a mesh) mades Pose mode laggy
I have a rigged character, and I wanted to join it with his hairs.
Those hairs were made from Curves, which I converted to a mesh, then decimated thanks to the Decimate Modifier and the Clean Up tools of the Edit Mode to decrease the number of polygons of the hairs.
But despite this, if I Join the hairs to the mesh, the Pose Mode becomes very laggy (In fact my character has less than 40000polygons, but the hairs has more than 300k polygons haha).
Do you have an idea here ?
Thanks !

I've partly figured it out.
Please be aware that I'm a beginner, so I would be glad to receive advices from a more advanced user.
1. First : the idea to join the hairs to the body is not necesseraly what I (or you) want.
My hairs are split in 6 parts. Some of them needs physics, other don't, but every parts needs to follow the rig (and so, the body) movements.
More, for performances convenience, it is better to animate the character displaying the less amount of vertices.
Then I parented every hair parts to the rig and the body without joining them :

Select the hair parts, select the rig, Ctrl-P to parent with empty groups.
Select the body (or the object the hairs needs to stick on), select the hairs, go to weight paint mode and transfer weights (Source : by name, applied to All Layers).

Then you hairs will follow the rig & body movements, but you can animate you character while muting the hairs in the outliner.
If you want to add physics to any parented parts (the hairs here), just follow the traditionnal steps.
Secondly, I managed to reduce the number of polygons of my hairs parts.
They currently have less than 100k polygons. It is enough  for me :
Pushing the decimate modifier further, and always use the Clean Up tools after (merge by distance, delete loose, degenerate dissolve) and finally normal recalculation to avoid glitchy behaviors.
I don't like this method as my topology got completely f*cked. I don't encounter issues from that but, if someone read that, please feel free to give me some advices.
PS : Please let me know if my english is not understandable.


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Apply volume to a spherical texture?
I have a quick texture applied on a UV Sphere. It is meant to be a spherical nebulae that I animate by keyframing the nodes settings (mostly color ramp, noise textures and color dodge mix shaders).
Here is a screen :

From here, I need 3 things :

Making my camera fly through this sphere to discover what is inside
Make the black areas completely transparent
Blur the limits of the sphere (it is too round now)

To do this, my though was to make this texture a volumed texture, keeping the sphere empty inside. Is it possible ?
Like if I had a spherical smoke domain with this exact texture, but Blender cannot handle it as far as I know. Plus, I'm a nood with volumetric textures.
Here is a quick reprensation:

Is there any way to achieve this ? Or, do you have any idea on how I can meet the results I need ?

You could try something like this.

The object I used for this is a simple UV sphere (I scaled mine up in edit mode to make it bigger - this might affect mapping values, I'm not sure - just be warned you may need to adjust those). Anyway, for the material, the main objective is to make 2 "spheres" using  Gradient textures. You need to make a large one and a smaller one - The large sphere will be your Volume, and the smaller one will be used as a Mix Factor to "subtract" from the larger one. In the image below where I show the smaller sphere, I inverted it just for the image example - The regular (non-inverted) output is what makes the mix factor, it just doesn't display well in a 2D image because it's a volume.

You can see from the mix with a Transparent BSDF (or Volume absorption if you want a "void" in the center), that the center sphere is "missing". It's a bit faint in the photo, but this is due to the nature of volumetrics.

The last thing I did was make a "noise volume", colored similarly to the colors in your image. You can use whatever texture you already have (as a volume).

Lastly, I multiplied those values with the large sphere's "color" to transfer the dark (absent) areas and the colors. The final result looks like this (In my image, I added the values to themselves a couple of times with an add shader to make them brighter - you may or may not want to do this).

That is a huge help you're giving me here !! I'll try this right now and keep you updated ! Thank you VERY much :) (and sorry if my english is bad)

Hey, no problem. Let me know if it works, or if you have any troubles. The hardest part for me was getting the right scale to make the "spheres" the proper sizes. I  ended up having to use .1 and .13 - strange numbers, I know, but anything else was either way too big or way too small. And BTW, your English is pretty much perfect.

Hey ! It seems that I can do something nice with your proposal ! Yet, when I add the multiple Add shaders at the end of the node tree, Blender gives me some purple colors artefact among the colors I choosed with the color ramp. It does not seems to appear on your screenshots, do you know why ? It seems that scaling down the sphere can fix this, but I really need a large scale scene.
In any case, I'll update you on the final results soon !

As I mentioned, I only used the Add Shaders to make the image brighter for the screenshot, you can get by without them. There are other ways to make your texture brighter if necessary, such as using a Bright/Contrast Node or an HSV Node (value component) between the MixRGB and the Volume Scatter.

Ok so, thanks to Christopher Bennett, I managed to create some kind of "volumed & voided nebulae" (by voided I mean with a hole inside). Using two gradient texture to artificially split the sphere in two was the good call ! Thanks Christophe, and to anyone : please check his comment where he explains everything :)

A little note here : I used an Emission node instead of the Volume Scatter node.
As I understand it, the Volume Scatter node is able to provide a high quality render, but alters a lot the colors you choose with the color ramp (especially if you scale up your sphere !), adds a lot of noise in the texture, and ask for a high level of CPU/GPU ressources.
So I used an Emission node, which provides a simpler texture I guess (but it is enough for me), and is processed wayyyy faster in Cycles.
Anyway it looks pretty cool for what I need to do (fly through it, and discover what's inside the "voided area" of the nebulae).