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Video with 50 FPS slightly off
I created a video and exported it in MPEG4 format with H264 encoder and 50 FPS.
When I import this file to Camtasia 2020 into a project with 50 FPS I notice a stuttering in the video. When I go frame by frame I can see that Camtasia is doubling some frames. Increasing the FPS to 50.95 in Blender makes the playback better, but still not perfect.
The file information (right click, properties) shows the exact same frame rate I set in Blender.
Now I am wondering if that is a Blender or Camtasia problem and how to fix it.
Can someone help?
Thanks and best regards,
Michael

It is most probably a problem with blender. You shouldn't have set it to 50 FPS though. You should have gone with 60 FPS. If you still need it in 50 fps, I would say you should render it in frame-by-frame form and then import it to Camtasia 2020 and arrange it in the order you want. Make each frame last 0.02 seconds. Then see, it will probably work. If it still feels a bit rough, you can smoothen it using the tool you have. I am not very sure though, this is my best guess. If you face any issues, please comment. Hope the answer helps.

I have to work with 50 FPS, cause I am combining video files and the camera files are 50 FPS.
I will try to work with the individual .png pictures. This is the way I render animations anyhow.

well, go ahead and try it in the png format. How long is the video though ? If you tell me that, I would be able to help much better.

The video is 450 frames or 9 seconds. The import and use of the individual .png files in Camtasia is possible, but it floats the media area since every single picture is considered one media file. Oh, and loading the project takes forever...

But honestly I think this is more likely a Camtasia problem. The video file that Blender creates plays just fine in a stand alone video player. It only stutters when imported into Camtasia.

I seriously don't know much about Camtasia but I seriously don't think it is a Camtasia problem. But, as I said, I don't know much about Camtasia, so could be it can't handle 50 FPS. As for the media problem, I don't know. Can you try switching to some other software, kdenlive. It's free. I think it should work there. As for repeating frames, can't you delete the frames where it stutters?

Camtasia Support just confirmed, that is only works with 30 or 60 FPS and not with 50.
I guess I have to adopt to 60 FPS then... :-(
There are workarounds like Aster17 suggested: manually deleting frames. But that also shortens the time of the clip. I hope the films from the video camera look ok when transformed from 50 to 60 FPS. Anyway, thank you all for your help!

well, you could use Kdenlive. It's free and is as good as adobe premiere.

hm.. ok. Will try! Thanks!

please do, it is open source and works with any windows version that is windows 7 and above. It also works with mac and Linux. Here's the link:
https://kdenlive.org/en/
If it helps, please tell me, I want to use it in my future projects too. Or you could directly render it in blender as video and then use it's video editor, but it isn't as good as kdenlive and takes a long time.

Kdenlive works very well. Importing 50 FPS is no problem and I can import MPEG 4 with lossless quality (which Camtasia does not support anymore) and also I can use the Matroska container (which Camtasia does not support). Kdenlive supports exporting in H.265 (which Camtasia does not support). A lot of advantages. But the handling is different (of course) and it takes a while to find all the "How to do"s that I know well in Camtasia. But I will continue with Kdenlive and see what the downfalls are (if any). Anyway, thanks for the tip!

Thanks you. I am happy my answer helped you. Would you mind upvoting my answer.

I would, but I see no option to vote. Maybe I need a higher reputation score before I am allowed to vote?

Do you see the arrow on top of the -1? Click on that and it will upvote. It won't show but I will still get the upvote.


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How do I enter rotation values in radians?
I personally prefer to use radians instead of degrees whenever possible, is just more comfortable to me. Is there any way to set blenders UI in a way where I never have to use degrees ever again and just interact with blender using radians?
I put this image up as an example, i'd just be really cool to be able to see rotation values as radians. Just a transform node in the geometry node system.
It'd be even cooler to see it as multiples of pi(not just input it as multiples of pi), but maybe that is asking for too much.

I don't get why this got closed. The chosen duplicate matches very poorly and does not answer this question fully, since there are more ways to use different units than to set them as scene units - you can enter a number followed by r in any angle input field to use radians.

This a peculiar feature of Geometry Nodes, Blender 3.0a. Typing into the field converts from degrees to radians. Feeding the field from, say, a Combine XYZ, or an input piped out to the modifer, accepts radians directly. I would hope for a revision to consistency, in time.

@MartynasŽiemys The OP might have mistakenly accepted the duplicate unaware of its effects. Reopened now, answer away

You can use radians in a few different ways:

Set scene angle units to radians in the Scene tab, Properties editor under units:

Or you could leave default degrees, but specify that you are entering radians in any angle input field following the number with "r":

This does not seem to work correctly with radians set as scene units for some reason currently.

Input fields also accept functions degrees() or radians(), but that's probably too much typing.

if you wanted to use radians with rotate operator's numerical input, you also can do that after entering advanced input mode with Numpad *:

You can do this very easy, actually, by changing unit system in the Scene properties:

Just chose Rotation - Radians in the Units section.

As you may already know, typing pi into an input field will get the value of PI to that input. So using the formula deg_value= radians_value * 180 * 1 / pi, I suggest you to just add a few more nodes to your setup :
1- A Math node set to multiply. The top value will be 180 and the bottom socket would be the value of your angle in radians
2- Plug the output of that node to a second Math node set to multiply. The other value would be 1/180
After doing so, you can plug the output of the last node to where you want to input you angle.

source: Stack Exchange

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

sort: votes


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Why is my VSE Importing a wrong image sequence?
I created a very simple one-minute digital countdown animation (using the add-on "Animation nodes" and using "text" as object) and it seems to be working just fine when i play the animation from the Viewpoint.
I exported the animation in a PNG image sequence and when I import that sequence in the VSE and play the video, it seems like the frames are sort of being anticipated:
It seems like there is always a frame misplaced in the middle of the preceding sequence, so, instead of seeing a smooth change from -let's say- 58 seconds to 57, i see 58 seconds, than 57 seconds (appearing for just one frame), than 58 again, than 57, than 56 (again for just one frame), then 57 and so on.
Overall, the countdown works but because some of the frames are being misplaced, it looks like it's glitching and of course i would like to solve that.
I've checked the PNG images directly in their folder and they are in a correct order, so it seems like VSE is importing them in a wrong one.
I'm new to blender and I would really appreciate any help.

are you sure it is imported in the name order (and not date order for example)? Also sometimes there are some refresh bugs, just close and reopen Blender and your file

Thank You so much! yes, i apparently imported the sequence in the date order instead of the name order, I haven't thought of that!

Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking.

Make sure that you import your sequence in name order and not in date order. Also sometimes there are some refresh bugs, just close and reopen Blender and your file.

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


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Image as plane only visible from certain angles
Sorry I'm really new to this  program still but I've had the issue where image planes are only seen from a certain angle for a while and I don't know how to fix it yet.In case it helps to know there's a purple plane , then the picture and then a transparent plane on top.

there must be faces overlapping, move your plane a little bit

I tried to move  it very far away to check but I cant even see  it from any angle now :(

please pack your images (File > External Data > Pack All Into .blend) and share your file (copy the link it will give you and paste it here): https://pasteall.org/blend/

I didn't get any link but i looked for the .blend file  with the same name , I hope  it was right.If it wasn't I feel bad so don't worry ill try to just  figure  out something.

How to share a Blend file

the link will appear in the URL field

https://pasteall.org/blend/b4442a5293ad439e96d6caa0868dabc9

It's a sorting problem from using Alpha Blend. Set the materials' Blender Mode to opaque.

@scurest that makes the  image underneath not visible  at  all anymore ,unless  im missing something obvious

as moonboots already said, select the image, press G Y and move it just a little bit to -y (you can hold shift during moving to move it slowly).
Then you get:

Alright thank you!!

If my answer works for u please check the checkmark left to my answer. Thanks.


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Separate a Mesh into several small meshes using Python
I would like to separate a mesh into smaller individual meshes using Python script. The whole mesh as shown in the picture has 500 m in length, and I would like to set up a series of parallel Planes of slicing each 5m so I can have hundreds of individual parts.
Pictures below show :
1)- Whole mesh
2)- example of separate parts
3)- example of parallel bisecting planes that will be used to cut the mesh and make individual parts

https://blender.stackexchange.com/questions/118884/python-bisect-mesh-into-n-parts-without-separate-loose   https://blender.stackexchange.com/questions/133086/slicing-an-object-in-4-parts


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Is it possible To Link Object Mesh Data without changing UV mapping?
I'm planning to use multiple "hexagon style" images in my scene but this will create millions of the same hexagon object and slow down the software. So after i generate hexagon objects with my geometry nodes, i apply the mesh, do an unwrap project from view, add a material, load an image texture, and then i would like to link ONLY the mesh data of all the hexagon objects to reduce the number of faces/vertices in the scene while keeping the image as is.

But linking the mesh data also links the UV map to the same coordinates as the active object i am  linking from hence wiping out my image. I read that it is possible to have different materials for the same linked mesh by using Link Material To Object instead of Link Material To Object Data. Is this also possible for the UV mapping? Or is there another method i should employ to retain the image while having shared mesh data?

Two possible solutions here.
First
Make a GN setup which will generate UV map for rendering, but keeps instances for viewport.

it's not clear to me how you did the UV unwrapping step since i
cannot unwrap each instance individually

I have default grid initially UV unwrapped. Then UV coordinates are transferred to instances using Transfer Attribute node. Last step - to make UV coordinate act like a pixel, I use Capture Attribute node in Instances mode, to make UV coordinates share per instance.
After that, I pass the resulted UV coordinate to attribute in the modifier settings:

And this attribute can be used in shader node tree as an attribute:

1.1
You can also pass color information instead of UV:

Second
Use object color in material, so that object and material will be linked

But colors must be set somehow, maybe using python


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Physics: Why does the cube with a hole and fit cylinder not work together?
I tested this simple setup where i created a 4x4m cube and created a 1m radius hole using boolean operation with a cylinder. So now i have tightly fit in the exact cylinder i used to make the hole and I've also reduced the radius of the cylinder by 0.05m with ALT+S to create this decent-sized gap as shown in the image below. Unfortunately it seems that this is not enough because the physics doesn't work. It keeps vibrating as if they are constantly in a state of violating the physics law of impenetrability. It does work if i decrease the cylinder by another 0.05m but that is way too big of a gap. I need the 2 objects to be as tight together as possible. How do i do that? I'm using collision shape mesh and tried all sources (final, base, deform) but unfortunately nothing works. I also checked the face normals orientation and it is correct; all faces are blue. File is here https://blend-exchange.com/b/ddzxasdA

When you choose Collision Shape > Mesh, the Rigid Body automatically uses Sensitivity > Margin with the default value of 0.04 whereas different shapes like Box or Convex Hull etc. have no default margin. There you have to enable Collision Margin to use a margin value.
If you set the margin to 0.0 on both objects, the simulation should become more stable. For even better results (but of course more to simulate) you could also increase Solver Iterations and maybe Substeps Per Frame under Scene Properties > Rigid Body World > Settings.

yes thank you very much! i just remembered this sensitivity option after i posted and went to the bathroom hahaha XD sorry

@HarryMcKenzie You're welcome, hopefully this still helps others. It's really not that obvious especially for beginners I guess, that rigid bodies have turned off the margin by default if you use any other shape than Mesh, and there it suddenly is. Most beginners make the mistake of using Convex Hull where maybe Mesh is needed, and if they are just told "switch to Mesh instead" without pointing out that margin detail, they can suddenly run into new problems which they didn't have before.

sorry i forgot to ask about the fall impact. it works on the fall but on impact it seems to not work though no matter how low or high i make the steps & iterations, it explodes on impact with margin 0 or 0.01.

@HarryMcKenzie I've set both objects to a margin of 0, then I go to cache, delete all bakes, then bake, and nothing explodes. Without changing any iterations or substeps, they are at default 10. Here's my updated file: fail-physics_new.blend Which version of Blender are you on? I'm using 3.1.2

cool thank you very much! :)


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Video renders fine until frame 487 but black afterwards
I imported an MTS video file format from my video cam and there is this weird synchronization problem where the video strip is stretched farther than the audio strip and hence slow motion effect.

So i added a speed control to be in sync with the audio which worked perfectly. When i scrub through the video sequencer everything seems fine but when pressing F12 for any frame after 487 it is blank. So when i render the video it displays from 1-486 and then is black for the rest of the video but the sound is still there. Any idea what is going on?

Might be the case that the Speed Modifier is shortening the video. Can you upload a .blend file so we can confirm this? I know the Speed modifier is annoying, you have to be kind of specific about how you add it and edit the clip after it's been added. It kind of completely untethers the actual clip playback from the in-editor length of the strip.

usually when video and audio length don't match it's because blender's framerate is different from the original video. Could it be that your footage was shot at 60fps and blender set to 30fps?

Make sure the the Frame Rate of the video matches the Frame Rate of the project, if not there will be mis-matching like in your case.


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"K" engraved on cube cracks with Bevel modifier
Hello i have a file attached at https://pasteall.org/blend/a98056a67ac44c44a31606c55252f763 where i have created 3 cubes each with letters N,Z, and K engraved on them. N and Z work perfectly fine with the bevel modifier and i have checked and made sure the geometry of each cube is perfect with no duplicate edges, vertices, faces but i cannot for the life of me figure out why the K cube cracks with a bevel modifier and also it doesn't bevel as smooth as N and Z which also have acute angles. Any idea what is going on?

Please add a closer view of the exact geometry around the crack, and maybe also one around similar areas on the other letters for reference.

@TheLabCat: If you would have opened the blend file you would have seen that it is not the geometry, but face orientation...

@Chris I wasn’t exactly in a position to open the Blend file at the time. But I meant to ask: how did you show the face orientation in the new file? I’ve never quite figured out how to do that.

@TheLabCat: i am not sure whether i understood you right, but you can see face orientation here:[1]: https://i.sstatic.net/S0KBS.png -> viewport overlays -> check "face orientation"

Your "K" has wrong face direction:

So select your K, then TAB -> edit mode, then Mesh -> Normals -> Recalculate outside

glad i could help


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Screw Modifier Destroying Normal in Blender
For some reason whenever I use a screw modifier my normals are being destroyed.
The below image is before applying screw modifier

Now after adding screw modifier, it looks like this

I have made sure all the transforms have been applied. Is there a way to correct this quickly?

I think for that the screw will always give bad result, because it creates edges between the start and end of the mesh at every iteration. You can see it for yourself if you lower the Angle below 360°. What you need is either an Array modifier + Rotated empty or an array modifier + a curve modifier

Hey :). Screw modifier works best with single edges and no faces. Reduce the mesh to a single edge, and it will work very well.

Ok, thanks! it worked with edges :)

For anyone who might have the same problem. The screw modifier doesn't work well with faces. So have only edges or vertices when adding screw modifier

Here is a workaround for that problem if you really want to use the screw modifier with faces.

step1: select your object
step2: Add screw modifier
step3: add solidify modifier
step4: play around with offset and clamp in the solidify modifier
until you get normal in the right direction.

Hello :). Check Calc Order and your normals should work fine straight away.

Well I tried and it didn't

Just to add to the existing answer.
You can control face orientation in the Screw modifier.
By checking Calc order (corrects normals) and using the Flip option (flips normals).

yes this works with edges but not with faces

If your mesh or part(s) of your mesh have flipped normals, here is what you can do :

Select your object and enter Edit Mode
Activate the Calculate Order option in the Screw modifier tab
Select the part of the mesh which shows flipped normals
Press the Space Bar(or F3) and search for the  Mirror (X/Y/Z Local) function
Expand bottom left  Mirror menu, then Orientation and choose Normal(instead of Local)
Find the axis that works for you (X, Y or Z)


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How to close Item count menu
I pressed ctrl shift A on a particle mesh and this poped up

I don't know what it is called might be an array mode Operator from looking up in key-bindings.
Now my problem I can't close this menu. I tried pressing the same key and more pops up. I also tried altshiftA but it does't close.
This is how it looks now.

Could you please give us a bit more informations? Which mode, which particle type? Ctrl Shift A does nothing here. But could be that i am in the wrong mode. I expect an addon here though. Since there is no default key map entry for shift ctrl a that is connected with particles.

This looks like a custom interface introduced by an add-on. Which add-ons are you using ?

@Gorgious Can you let me know if there anything called an Array Mode Operator in Blender? or is it an addon? I could see something called Array Mode Operator when I search in keymap in preferences. I think that's causing the issue.

This is definitely added by an add-on. You can check enabled addons in the preferences


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How to change what an object is pointing at
I'm creating an animation of an airplane and was wondering whether there is a simpler solution to make it pointing at where it is going instead of manually animating it. I found this question: How to make an object point in the direction that it's going?
The answer suggest using paths, however it is very old and I can neither find the follow path constraint in blender 2.8 nor access the information in the blender wiki link as the page cannot be found. So I chose to ask a new question.
So here's my idea: We have already animated the path. So would it be possible to copy the object's motion to a point object (or any other object that won't be visible in the final render) and off-set it by one frame or so. Then the point will be one frame "in the future". This should work, however I cannot figure out how to change where the airplane is pointing at. Is there such a function in blender and how can it be accessed?

I recommend investigating the tracking constraints. More specifically, the Damped Track constraint, which is the only one (of the track variety, anyway) that seems to work as expected right out of the box.

If you just need to point an object to another (for example to an empty) you can use an "object constraint" and targeting to the empty.
check this video:

perfect! that's exactly what I was looking for.


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Does the compositor affect image quality?
I noticed that the compositing is applied after the image is rendered. Does this mean that when working with an 8-bit Output that the compositor can affect image quality negatively? (i.e. artifacts like banding etc.)

Am noticing major degradation in image quality when outputting from the Compositor; mxf footage brought in, zero compositing and output to exr, brought back into resolve to cross check notices a lot of stepping in the scopes which can only mean that something is being lost. have seen the same with prores footage as well. b3d 3.2.2

No, the compositor will not degrade rendered images.
The compositor works with 32bit float precision, in scene referred linear (meaning that there is way more information that what can be displayed in the monitor).
Of course, there could be intentional or unintentional degrading in the compositor caused by incorrectly connected nodes and/or poor judgement by the user.
A likely source of image degradation is the use of highly compressed images in lossy compression schemes (like jpeg or mpeg), in which the the original image will suffer corruption with each subsequent cycle of decompression and re-compression.
As for Color Banding, it would happen when the image is saved to 8 bit formats, as this method of encoding cannot resolve subtle color gradation with only 255 levels for each color. Areas of similar colors, and dark, almost monochromatic gradients, will suffer greatly.
To disguise banding in the rendered image, use dithering.
Note that even if the image is saved as 16 bit or 32 bit per channel, it is possible that it cannot be displayed at a better quality: Most monitors display only 8 bits per channel (and some even less than that). Banding then is inevitable (just pause any of your favorite movies during streaming and you will see what I'm talking about). Banding might disappear if the higher bit depth images are displayed properly in a 10 bit monitor or better (retina display or any professional grade monitor or video projector)

As for if I've tested it - yes. I've worked with arri and r3d footage converted to 16 bit half float exr to import into blender and am noticing a degradation on the export. I'm noticing it on 8 bit mxf files. Am noticing it on prores smpte 2084 1000 nits material. The issue is consistent - so my query is IF the compositor's export is degrading the material in any way or if it's being affected on the import. The primary reason for this is that if there is a degradation in footage, it renders B3D's compositor useless for production VFX as it would kick back every time from DI due to affecting the primary source material. I've also exported to linear 16bit tiff files and am seeing some degradation as well so possibly it's due to the import. Suffice to say, I think this needs to be addressed if there is a loss of data.


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Overlay video to active camera view
I want to recreate a scene from a video. There is lots of camera movement which I want to recreate as accurately as possible. Is there a way to overlay my reference video to my active camera view (e.g. half-transparent) so that I can improve the accuracy of my process?
Until now, I've been trying to have a seperate window with the video sequencer, but this is not very accurate.

If you want accuracy you should track the scene, solve the camera and reconstruct the camera moves and 3d environment. Watch the "match track blend" series of videos by Sebastian Keoenig to understand the process https://www.youtube.com/watch?v=U7AjIL_fDtU
Then there is fspy (https://fspy.io/), a piece of software and a blender addon to estimate camera placement and lens based on the vanising points in an image. worth trying that too.
Manually placing the camera is not only tedious, but very hard to do accurately just "by-eye', as it involves matching field of view, distortion, camera rotation and placement on top of estimating the scale and distance to the 3d objects. The camera placement, rotation and field of view is only valid for a single point in space and not others. That is a highly complex task.
If you still want to painfully guesstimate it yourself use the camera background image feature.

It will display an image (or video frames) as background in the camera view only.
To match it with your scene lock the camera to view as explained in the following post:
https://blender.stackexchange.com/a/135150/97988

thanks for your reply. I might try using camera tracking, however in some parts of my shot there is no object to track (only moving objects). I'll nevertheless give it a try.

Note that there are two functions when doing tracking: one to reconstruct camera motion, other to solve objects motion.


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HDRi not visible when using Mist pass
I am using Blender 2.83 and want to create a scene with a lot of fog, so I've been using the Mist pass. However, this makes the HDRi invisible. Is this a limitation of the Mist pass or are my settings wrong?
These are my mist pass settings:

And my compositor looks like this:

The mist pass effectively fades out your scene the further it is from the camera (ie, the more ‘mist’ that light ray has had to travel through). The HDRI by its very nature is out at an infinite distance and, therefore, is completely obscured by the mist.

But it can be mixed with the render layer to a lower value in the compositor, so that the HDR shows.

@susu Quite right. Actually, to allow the HDRI to show through you could add a Maths node to Multiply the 0.0->1.0 range of the Mist by a fractional number (eg 0.8) to limit the amount of mist. Or use a Minimum maths node to limit the maximum mist, depending on the desired results.


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Selective transparency?

I'm trying to create a scene in which an object is transparent with respect to some objects and not others. The screenshot above shows kind of the effect I'm dealing with. I have here a cube with one face (on the right side) removed, in front of a backdrop and with a sphere inside it. I want the cube to be transparent enough to show the backdrop and anything else in the scene that I put behind it; at the same time, the sphere inside the cube needs to be completely invisible, except when seen through the open face.
Effectively I want the cube to behave in a way similar to an invisibility cloak effect, but the cube itself needs to be visible, yet transparent. I keep thinking I've found a way to make this work, only to run into problems. I'm out of ideas now but not yet willing to give up on the scene. Ideas?


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Suddenly rendering a double image
The render (cycles) seems to be rendering the scene twice, slightly enlarging one image, and superimposing it in the same render result. The result I'm getting is as if seeing double. I have only one render layer, one scene, one camera. Test renders worked fine until I added a denoise mode in the compositor and moved the camera, and now I can't remove the effect, even by replacing the camera.
Incidentally, I tried switching to eevee just to see what happens; it renders only the HDRI and nothing else. This is even more perplexing.
Sorry if this sounds terse. I meant go to go bed two hours ago and I'm frustrated I can't render this overnight now.

I found out the problem: I have fluid simulation in the scene, and the camera was reflecting off the domain's bounding box. The simulation only kicks in partway, and I forgot that this would cause the domain to resemble a watery cube prior to that point.

I had a similar problem. It was because I had my Hi Res and low res images enabled in the outliner. I had to disable the little camera next to my Hi res image, now all is fine.


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How to deal with long, thin triangles when baking maps?
I’m currently encountering some visual artifacts when trying to bake an image from a specific UV map. See below an illustration of it:

This UV map has overall some nice properties in terms of angular/surface deformation. None of the triangles overlap each other as well. However, my issue comes from the zones circled in red: here are some long and thin triangles, less than a pixel’s length at their thinnest.
I use this UV map map to bake a Vector Displacement Map, ie a map storing the displacement needed to recreate an object from a plane. The map produced through this baking looks like so:

Sadly, the thin triangles of the UV map create some problems after baking the map and trying to recreate the object from it:

The areas circled in red show zones with visual artifacts, where some triangles essentially cross each other. Note that the circle at the bottom of this image corresponds to the same zone as the bottom circle of the UV map image.
My intuition is that because these triangles are so thin, when baking from this map, they essentially sometimes “fight” for the same pixel, leading to unpredictable results. A possible solution would thus be to bake the map by randomly sampling from it until the result stabilizes, the same way we do for a render. I’m however not sure if this is possible currently in Blender.
Note: In this project, modifying the UV map is sadly not really an option. It’s created automatically, and after some efforts the map that you see here is the best that I could get.

Everything should be shaded smooth when baking.

@MarkusvonBroady not necessarily EVERYTHING, but there does need to be at least some smooth shading done to the vertex normals. It depends on the object. A hard surface object might have sharp edges, while an organic object would be 100% smooth shaded.

I don't understand why altering the UVs isn't an option. Aside from what has been mentioned re: Hard/Soft edges & vertex normals, that's what needs to be done to fix this issue. If you can't do that then you need to revise whatever algorithm it is that is automatically unwrapping the object. You're never going to get super clean bakes if you don't spend at least a little time unwrapping the object cleanly.

@MarkusvonBroady I just tried it but sadly it does not seem to change the quality much.

@Jakemoyo The challenge here is that the boundaries of the UV map need to be constant. Since the goal is to bake a vector displacement map, if the boundaries aren't fixed then the vertices are going to be pulled from a larger surface than covered by the object, resulting in ugly artifacts. The UV map here is essentially the best that the state of the art produces, hence why I'd like to think about solutions that do not focus on modifying it further. It also has nice properties in terms of area/angles preservations, so I think it's reasonable to find a way using it as is.


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Geometry suddenly got merged together like Union effect in my Object
Please help i don't know what i did. why all of my geometric shapes got unioned together at some point in time. I used to be able to select each shape (cube, sphere, cylinder, etc) with "L" in the whole object in Edit mode. I only remember doing "Cleanup -> Merge Vertices 0.0001m" but never did i intend to do anything to merge (union) everything together into one interconnected geometry. What could i have possibly done?

Well, if the geometries were very close together and you merged them using the Cleanup > Merge by Distance tool, they're gonna... merge. You can only undo, or manually select and separate them. Are you saying they got merged even though they were not close together? Please be more specific, with screenshots or files, if possible.

You can select all and press P > By loose parts to separate your mesh islands into individual objects first, if that's what you want.

yeah i already tried but they are already merged coz i did merge with a slightly higher value than 0.0001m

Yeah, you have to do it before merging :)

If the geometries are very close together and you merge them using the Cleanup > Merge > by Distance tool, they're gonna... merge. You can only undo, or manually select and separate them afterwards. If you're unsure about a cleanup operation and would like to keep mesh island intact, you might wanna first separate them into individual objects with P > By loose parts. Now with multiple individual objects selected, you can Tab back into Edit Mode and do a cleanup of all of them at once without having them joined together.


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Fluid loss in 2.83
My fluid simulation is a rotating cube filled with water. I noticed, that the volume of the water gets less and less while the cube is moving, but there is no fluid escaping from the cube.
During my research, I have found this problem with earlier versions of Blender and the Flip Fluid addon. Version 2.80 had an option to compensate this effect called "Impact factor" (see: https://docs.blender.org/manual/en/2.80/physics/fluid/types/obstacle.html).
In version 2.83 I cannot find this option anymore.
Here (https://github.com/rlguy/Blender-FLIP-Fluids/issues/436) it was stated that the problem is related to fluid particles sticking to the sides of the obstacle.
Does anyone know, how to fix this? Is this on the bug list?
Thanks for your help!
Mick


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Fluid - Sudden splashes during calm down
I am pouring a liquid onto a surface with the domain as boundary. Domain resolution is 300 and I am working with some viscosity. The inflow is active for 1 second and then I want the fluid to calm down and sit still. But while the liquid is calming down, I get sudden upward splashes of liquid.
Does anyone know how to prevent that?
Thanks!
Mick

Id say rerun the bake. Fluid Dynamics are very complicated and your computer probably had some sort of Error which reslulted in a sudden net plus of Energy, thus creating the splash.
Another option may be resonance. See, the Fluid still has a lot of energy even if it is close to a resting state. And as all Dynamic systems tend to do, the Fluid kind of equalizes itself by moving. And so what can happen is that a lot of Energy suddenly gets released because a lot of Particels just happen to hit the right frequency. There is something similar that happens in the real world, but that is related to Quantum Mechanics. And Blender dosnt take those effects into account as far as i know.

I already tried multiple times with different scenes. It always happens.
Reducing the domain resolution to 200 fixed it, but it should work with higher resolutions as well.
If you want to try: create a domain with resolution 300, then activate in infill for 2 seconds and let the fluid bake for 10 seconds. You will see that after 4-5 seconds the water jumps up.


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How can I make a baking soda model in blender?
I am trying to make a baking soda model but I cant figure out how to go about making it. Does anyone here know where I can find tutorials on how to do this. I searched all over Youtube but couldnt find any that involve making powder and exporting it with UVs.

you have some solutions for powder: https://blenderartists.org/t/how-to-model-a-pile-of-powder/550293/6  https://blender.stackexchange.com/questions/5235/how-can-i-simulate-powder-with-a-particle-system/5236#5236   https://blender.stackexchange.com/questions/44606/how-to-make-an-object-appear-to-be-buried-in-sand   It would be interesting to know how you did it  ;)


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How do you change the 'efficiency' of a mirror-like reflection on glass?
I'm looking to create the glass top on a coffee table. My reference in real life is basically a piece of glass. I can see through it easily but not perfectly, so my Transmission is set to .87 to make up for light loss through the glass. The glass is also reflective, so the Roughness is set to 0 for the most part. However, this causes my Blender glass to become mirrorlike. While the reflections should be 'mirror' accurate, they should also be much darker. What setting on the principled BSDF would I use to effect this sort of stat?


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Pixelated/Blocky Effect in Smoke Render in Blender 2.82a?
Here is my rendered output of a small sample to demonstrate the issue I'm having: https://gfycat.com/obedientkindlyguernseycow
When I look at any of this in Blender's rendered view, I don't see the blocky artifacts in the smoke that you see here. So I'm not sure how to fix this in my renders. Has anyone encountered this before? Viewport render is at 256 and the Render setting is 1024.
The domain was baked with 1024 Resolution Divisions with 12 max timesteps and 15 samplng substeps for the emitters.
I've also noticed that the effect is more pronounced in the animation output vs in my still renders. But I thought that each uses the same settings?

TL;DR,
Use png, exr, jpeg with high quality... image format to save as sequence and encode them in other program to video. eg. Adobe Premiere (Media Encoder), DaVinci Resolve

Depend on your video encoder, keep in mind that most of the video format are lossy-compressed by default, which means some data are actually loss in the video from the source.
And most of the encoding algorithm assume that one frame should be similar to next frame, to reduce the space requisition for similar color. So if your explosion make "fast and high dynamic color change". Your video will perform a low resolution, or blur, chunk image sequence, if your video bit-rate is set as a relatively low value.
You can set your H.264 render parameter to lossless to suppress that mosaic effect:

Or you can use AVI Raw format to save a BMP-sequence-like video format.


text:
How to create a floating flag that isnt pinned/hooked?
I've seen how to create a flag using cloth simulation, and pinning corner vertex etc. However what Im wanting to do is have the flag fluttering in Wind, but without having the corners pinned (or at least less noticeably). It would be quite intentionally unrealistic, in that its like the flag is floating in a set place BUT the cloth is still flapping as per normal in wind.
Note: I've tried Hooks with lower Strength on corners, but they remained statically pinned. I thought each corner Hooked to an Empty, with strength of 0.2ish might make them float enough, but didnt work.
Im new to Blender so may simply be approaching wrong way.

instead of a cloth simulation use a distortion map and a displace modifier. https://blender.stackexchange.com/questions/15036/how-to-animate-the-displacement-of-the-displace-modifier

Hi @ArtUnion, may you post your minimum working example with hooks that we can build off of?

One way out is combination of shape keys and proportional editing applied to a subdivided plane. Subdivide a plane and make each proportional edit a separate shape key to animate later. It takes time but the wave may be regular if realism is not your goal.


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How to use one object color as a factor for another objects color/glare?
I have an object with wave gradient texture. Above it, I put many balls, some of them touch the first object. I want to make color of the balls to be different depending if the ball touches green or white area. Or to make balls glare if they touch green area.
How should I set the balls material to achieve this? Or should it be done in compositing?

Is this static? Or are the balls moving?

It is a static image. In eevee engine.


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Material not applied properly
I was just testing some materials and i made a simple jeans model so i can put the denim material on it, i was using the lily scapper add on, when denim material was put on only a small part of the model had the material and the rest only had like a stretched version of the texture like blue or something.
When i went to uv editing to edit the position of the faces, i select faces but on the uv editor they show up as an edge. If anyone can help i would appreciate it. Thanks

Don't know if this will work, but here's something you can try:
first remove the texture, go into object mode, select the jeans, and apply the scale using ctrl+a.
Then go into edit mode with your jeans, use "a" to select everything, and hit u -> UV unwrap. I think this will generate a different set of faces.
Finally add the texture back on using lily's surface scraper.

Thanks man, appreciate it


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Very low heat weight of my model after auto weight
I am using Blender 2.90 version, and I am in the part of adding armature. I create a "Human (Meta-rig)" than I use "armature deform with automatic weights". But when I making the pose, it seems that the auto weight doesn't work... please tell me how do I fix it?

If a bone doesn't have full control over part of your mesh, another bone is partially influencing it. Make sure the beginning and end of each bone are touching the mesh, so the automatic weighting works better.
In your screenshot it looks like bones from the left leg are influencing the right leg and vice versa. To get rid of this effect select the left leg in Edit Mode (e.g. go to wireframe, Box select the vertices from the left leg) and then remove the weight from any bone in the right leg or assign it a value of 0. Then repeat the other way around. (I recommend using "Remove")

I tried what you said, but nothing seems to improve. After I opened the early file, this problem did not happen again, but I still don’t know what caused it. btw, thank you for answering my question.


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Separate Mesh into parts based on spacial geometry and not linked-rule
I was able to run a python script that cuts my mesh into several meshes based on the following thread :  Bisect mesh into n parts, without separate 'LOOSE'. However, some of these parts should still be separated based on the fact that they are spatially not linked.
The images below explain the issue. Basically, instead of one mesh that encompasses the 5 geometries, I would like 5 separated meshes in my scene.
I tried to different selection tools but I couldn't get the desired effect
Any help would be much appreciated.

com/JAOQt.jpg

Please don't ask what is basically the same question twice https://blender.stackexchange.com/questions/237993/separate-a-mesh-into-several-small-meshes-using-python  , instead edit any extra information into previous. Appears to me  the regular separate by LOOSE parts operator will turn the last mesh shown above into 5 parts.

oh sorry for that ! will do for next time. At first, Separate by LOOSE didn't really work but after correcting the mesh (merge vertices by distance), I get clean separation. Thanks a lot BatFinger !!


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Weird viewport when X,Y,Z coordinates are really high
I have a mesh that is geo-referenced using some global reference where my X, Y and Z coordinates of the center are really high.
When I Align my view around the 3D cursor (same as the mesh center), I have a weird viewport where several faces are transparent.
When I move the whole model into X=0, Y=0 and Z=0 for example, the problem disappears (picture 2)
I would like to keep working with the original coordinates though. Any idea why I have this effect ?
Thanks for your help how to solve this issue,

Reminds me of the game Outer Wilds, due to floating point precision everything works better when the player is at 0,0,0 so instead of moving the player character they apply the opposite force to every other entity in the game.  It's all about your frame of reference.

what should I do then ? make a delta transformation, get everything move to 0,0,0, do what I have to do and make the same delta transformation again ?

I'm not that familiar with python but scripting might provide a solution.  If you parent an empty at the current origin, you should be able to move your mesh around, apply the location, and the empty should have the inverse transform. (If I'm thinking about this correctly :p)

"I would like to keep working with the original coordinates" Why, is it for the convenience of entering familiar coordinates? I'd advise moving everything as close to world zero as possible a known easy to work distance like say 500000,400000, so you don't have to do a lot of mental calculations. Coordinates will still be recognizable minus a few thousands


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Polys are stretched when posing. Weight painting doesn't seem to fix it fully

So this skeleton isn't a universal one, it's from Grand Theft Auto V and it's very strict on the amount of bones and bone type, so changing the rig is out of the question. I tried using subdivide on the part of the leg and it seemed to look a bit better, but it would not smooth out afterwards.
I'm running Blender 2.8.

Here is my .blend
https://blend-exchange.com/b/4emLsaWr

It's not the rig, it's the geometry of the mesh.  It's stretching because there's not enough geometry for it to not stretch.  See this answer for details.

The problem is duplicated vertices and bad Custom Split Normals.
First, select the mesh (lowr_000_r_high), go to Edit mode, press A to select all, then M > Merge By Distance to get rid of 8871 duplicated vertices.
Furthermore, it looks like the mesh is optimized for a game engine. It has tris, Auto Smooth is enabled, and there is Custom Split Normals Data. The Custom Split Normals Data seems to be messed up at the knee area.
You can fix the shading this way: (The order is important!)

switch to Object mode, right-click the mesh object, select Shade Smooth. It will look worse. No worries.
add a Weighted Normal modifier. It goes after the Armature modifier (see screenshot)
apply the added modifier. This will recreate/override the Custom Split Normals Data. The shading will change a little bit and there is a warning. This is because the modifier is not the first on the stack. But the result will be fine.

Note: If you don't like the shading you need to delete the Custom Split Normals Data and disable Object Data Properties > Normals > Auto Smooth.


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How to change Blender's default UV editing display
I'm new to blender but have experience with 3DS Max.
Inside blender when you enter the UV editor, only the faces that are currently selected in Edit mode appear on the UV grid. What I would like is to have all the faces of the object displayed on the UV grid without the need to select each individual face. And if possible also have what I currently have selected in the UV Grid appear in the edit mode so I can see what I'm editing easier. Are there preferences, settings or a plug-in that might help me or am I stuck with Blenders default UV Editor.

The UV Sync Selection button should do what you want:

You are a wonderful human being thank you for this. it is exactly what I wanted.


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Blender crashes when rendering at full resolution
I created a scene and after some test renders at 50% resolution, I want to render the full resolution (which is 1920x800). However, blender always crashes after a few minutes, often even before it starts sampling.
My system specs are:
CPU: Intel i7-6500U
GPU: Nvidia GeForce GTX 950M (2GB VRAM)
16GB RAM
which is a pretty low-end setup considering the complexity of my scene (about 700 million vertices), but why does blender crash? The test renders worked fine; they took around half an hour to render. What is different when rendering at higher resolutions? Shouldn't blender just take 4 times as long to render it?
I would attatch my .blend file, but it's too large (600MB)

A few choices: Render in parts that your computer can deal with and composite later. Or simplify your scene. Or use a render farm. Or render using CPU. Do you really need 700 million vertices? 3D is all about faking and optimizing, try to use detail only where it shows.

@susu thanks for your tips. Unfortunately, render layers is not possible with my scene because there is lots of fog. I already tried to reduce the vertice count as much as possible, but I created a big landscape with 130.000 (low-poly) trees. Render farms might be something to look into. Anyway, thanks!

as @susu said use render layers.  using render layers with fog is always possible, have done so successfully myself because was only way to render in reasonable time. also,  2GB VRAM is not alot, and blender will use  that up quickly. Simplify things, remove what the camera wont see and use small textures.

This answer probybly depends on the scene, but I found that reducing the tasks Blender has to do helps: For me, this was turning off motion blur (which I will later add in a video editing software). Other approaches could be reducing light bounces or samples.


text:
How can I do multiple "renderings" of one scene in one render?
I have a scene in which I want to reduce noise/fireflies by the method illustrated here, i.e. rendering twice (or in my case 4 times, but the theory is the same) with lower sample count but different seed and combining the results with blending mode "Darken".
My scene is an animation with ~500 frames so rendering it twice would result in a lot higher used storage. What I'd like to do is tell blender

render frame 1 with render seed 1
render frame 1 with render seed 2
combine those two frames to one using darken
combine my compositing nodes to the result of step 3
output that as one file
repeat for every other frame

it doesn't matter for me if steps 1 and 2 are done at the same time (if that's even possible) or not as I assume the total duration would be the same. Preferably this should work without python scripts since I plan on using a render farm which doesn't support those.
How can I do this?
Blender version used is 3.3.1 but if there's a solution that requires 3.4 updating would be no problem.

btw I'm not very happy with the title of this question but can't think of something better - suggestions/edits are welcome :)

are you looking for automating this without python? https://blender.stackexchange.com/questions/5017/stacking-cycles-renders-in-the-compositor?rq=1

The comment by R M K pointed me in the right direction (thanks!) and I've been able to figure out a solution myself.
What I ended up doing was creating multiple scenes (within the same file) for which I copied all objects and render settings from the original scene and then only gave them a different seed.
In the compositor I then used a node setup like this

with some other nodes that are not relevant to the denoising behind. I suppose I could also have enabled the other passes (Emit, AO, Depth) in every scene and apply the same process to them but considering that they didn't have any noise/firefly problems I just left them as they are.
During rendering, every scene gets rendered separately1 and then composited at the end. Since you can easily get away with 1/4 of the original sample count, the overall time needed is pretty much the same.

1 for some reason (maybe just a bug) every scene other than the original doesn't show any progress during rendering (it's just a transparent image) but it still works and after it's finished you can preview those scenes in compositor.


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How to remove black patches under hair?

for some reason, whenever i use blender cycles the hair get weird back spots under it? anyway to make the black spots disappear or transparent?

That looks like the hair strands that are on top of other hair strands are shadowing the ones underneath. Try adding more light bounces for transparency (In the Render properties tab, Light paths, Max bounces)


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How to import data in IK
I've been using blender for a few months.
I made an IK (Inverse Kinematics) model and have 3D position data of hands.
What I've been doing was manually typing in the x, y, z coordinates in each frame and setting it as a keyframe. So when I had 10-second data in 10Hz, I had to put in 100 data points.
Is there any way to import the data of body points? (e.g., head, hands, pelvis, etc.)
As a graph, CSV file, or anything?
Thank you.


text:
How to rotate collection instance with reference point
I have a question concerning precision edition of a geometry.
Here I'm simply trying to align a window collection instance with a given axis.
Logically, with a pivot set to the instance's origin P0, I would like to select P1 and then P2 to match edge [P0 P1] with [P0 P2].
Actually I can snap on P2 but geometry just tries to ture 90 degrees.
Does anybody has a solution for this?
p.s. Please concern that solution has to be made without manipulating original collection itself. Just think about placing identical windows along walls that doesn't go parpendicullarly.
Happy blending!

The first job is to get the origin of the Collection Instance in the right location and orientation with respect to its component objects.
When a Collection Instance is created, all its component objects retain their World Transforms, with respect to the collection's origin (represented by an Empty). While you can move the origin of a collection using the Header > Object > Set Origin menu, it's probably least confusing to keep the Collection origin at the world origin while assembling. You can hide the source collection, and still work with its instances.
Once that's done, you can align the instance as you would any other object. (You can search for various ways besides this to do that, here on BSE)

Here, the original collection is shown at the origin, as created. In this example..

A Custom Orientation was created from the sloping target face. (The '+' in the Orientation dropdown)
The 3D Cursor was snapped to the face (ShiftS)
The (wireframe) Instance was snapped to the cursor (ShiftS)
With the instance selected, and the Custom Orientation active, Header > Object > Transform menu, 'Align to Transform Orientation'

You can align multiple instances in one move.
The Instance's local axes are shown in the gizmo.

Thank you so much. Always surprised how blender community is supportive to a newbe like me.

You can snap the rotation without modifying the origin point.
While not not as elegant as @Robin Betts's answer, it's fast :).

Enable snapping to Face and check ✓ Align rotation and  ✓ Project elements
Drag the rotate tool anywhere in the 3D viewport, it will snap (but with the wrong face)
Correct the rotation in the sidebar, so it's only rotated on the Z axis

Note:
If nothing else, this method will give you the exact angle, so you can enter it manually into whichever axis you want :).

Yours is just as elegant.. and OP could construct the instance to be the right-side-out.. I was going for centering to the face, too, but maybe that's surplus.

Nah, the more I play with it, the less it works :). The custom orientation is way more practical.

gif is always awesome! Thank you for the kind response.

Just now I've tried it and works perfectly. The thing now concerns me is the meaning of those options. I think I understand align rotation to target - it means object will be rotated to match it's z-axis with target's z-axis right? But what 'Project individual object I do not understand. Orienting in blender is still kind of confusing. Can you recommend any text or video resource exploring advanced transformation system of Blender?


text:
Loading a movie strip into cache without using proxies
I have tried searching online, but I cannot find a clear answer...
I want to make a movie strip easier to edit by caching its frames to RAM. I have configured the Sequencer Cache Limit to 8192 MB, which should be more than enough for the <1 GB video.
My question is: Is there an easy way to automatically cache all of a movie strip's frames?
Individual frames get cached when I have the playhead on them. Playing the video from the beginning stutters a lot, so the playhead skips frames and caches very few of them. Is there a better way to cache movie strips?
I know proxies are a thing, but if possible I would rather use my RAM than fill more disk space.
Do you guys know of a Blender feature or custom script that allows for automatic movie strip caching? Thanks for your help.

There is a wip patch which will cache to disk, but it is not ready to be included in Blender yet: https://developer.blender.org/D5524


text:
Jagged edges using a toon shader and Evee
I am trying to create a cartoon style render using evee with light reflections on the material (wich is suposed to be metal). I tried everything like subdividing, auto smooth, changing shadow resolution... Nothing seems to work.
My node look like that ( the part with colors really close together is to make the reflections apear)
If anyone has an anwser to this problem, it could help me a lot, thanks :)

Can you show the rest of your node tree?

Yes, it looks like that :  https://imgur.com/a/nxxP2VW

Try making the light source really really small by scaling it.


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How do i "disable" or recalculate modifiers?
I have a cube with an array modify, and a surfacedeform targeting a plane. The plane has a curve modifier targeting to a circle. (this is a simplified version of my issue).
When I change the size of the array, the surfacedeform breaks, so I try to rebind. However, because the plane has a curve modifier, it cant bind. Is there some way to do this without completely removing the curve modifier (hiding doesnt help)?

You can try using a linked duplicate (ALT D) without any modifier and set this as the target of the surface deform. Parent it to the base object so they move and transform together

@Gorgious that works great, thanks! so i create a linked duplicate of the plane remove the modifiers, bind the array to that, then i just change the target and it applies as expected! fantastic!


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How to form a tapered stamp from an SVG
I am trying to make a stamp from an SVG. I have found a model on thingiverse that demonstrates the desired outcome well.
Given an SVG, and a "body" mesh:

I would like to make a stamp where the body tapers into the impression:

I am very new to blender, and have been trying all manner of boolean operations and extruding, but am stumped on how to create something as elegant as this - preferably without lots of vertex nudging.
I believe the example was done in fusion 360.

This result can be achieved easily using basic operations.

Connect parts of your shape, so it only has one edge (select 4 vertices and press F and repeat)
Connect it to a circle (or your handle)
Add some ridges and move your shape upwards to taper it.

Make one outside edge and connect it to a circle (or other shape)

Extrude it to make a handle (unless you already have one)

Add some ridges and move the shape upwards, it will taper nicely.

C'mon you're making that look easier than it really is...

Wow, thank you so much. Seeing your technique has literally quadrupled my competence.

Happy to help :). If you get stuck anywhere, feel free to ask. Good luck.

Taking the inspiration from Jachyms answer I managed to produce the following stamp:

My technique was slightly different, as the geometry of the SVG is pretty complicated and I kept losing track of which faces I wanted to keep (is there a way to mark faces in some way?), but I would not have known how to approach this if it weren't for Jachym.
For those interested, my approach was:

extrude SVG
"Fatten" one side to get the taper
Reduce the number of vertexes on the fattened side, by selecting and merging by distance
Manually nudge some of the vertices so I have a defined permimter
Create a circle
Manually bridge the vertices (I suppose I could have used edge loop, but I kept losing count of the vertices - ADHD fun). Maybe theres an easier way to display selected vertice count?
Extrude out the handle.

No doubt the geometry is appalling (its evident that there is lots of internal criss-crossing of edges - maybe there is a way to easily clean this up?), but it seems to slice ok for 3d printing, which means its ok for my purposes (pottery stamp), but I appreciate that Jachyms answer is the correct approach for this kind of thing.

Every solution that works for you is a good one :).
Btw, the (selected) vertex count is in the bottom status bar when in Edit mode.

Thanks - I cant believe I couldnt see it staring at me :D

You can make vertex groups of vertices implicitly selected when you select faces, or you can mark faces by giving them an arbitrary material ... you can select by material just under the material slots. That does mean you have to have two materials assigned, but they can look identical.

Thanks Robin - that will help a lot.


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Check overlapping in pose position
I have the following code to check if two objects overlapping and it's works well, I don't understand how to check overlapping for objects in pose position
Source of this code: https://blender.stackexchange.com/a/150047/97742
import bpy
from mathutils.bvhtree import BVHTree

# Get the objects
obj1 = bpy.data.objects["Cube"]
obj2 = bpy.data.objects["Suzanne"]

# Get their world matrix
mat1 = obj1.matrix_world
mat2 = obj2.matrix_world

# Get the geometry in world coordinates
vert1 = [mat1 @ v.co for v in obj1.data.vertices]
poly1 = [p.vertices for p in obj1.data.polygons]

vert2 = [mat2 @ v.co for v in obj2.data.vertices]
poly2 = [p.vertices for p in obj2.data.polygons]

# Create the BVH trees
bvh1 = BVHTree.FromPolygons( vert1, poly1 )
bvh2 = BVHTree.FromPolygons( vert2, poly2 )

# Test if overlap
if bvh1.overlap( bvh2 ):
    print( "Overlap" )
else:
    print( "No overlap" )

Try replacing the # Get the objects part of that script with the script below.
# Get the objects
ob1 = bpy.data.objects["Cube"]
ob2 = bpy.data.objects["Suzanne"]

# Get the evaluated objects
depsgraph = bpy.context.evaluated_depsgraph_get()
obj1 = ob1.evaluated_get(depsgraph)
obj2 = ob2.evaluated_get(depsgraph)

See types.Depsgraph

It's working! Thank you


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Why wont my imported obj appear, it says its in blender but I cant actually see it
basically, in the little sidebar on the right, it has everything and it shows that my object is in the blender, but when I look at the actual grid thing, there are arrows and I'm able to move an invisible something however the object I can't see it (its a Roblox Character)

usually the issue is with the scale. Youe model might be too big or too small.https://blender.stackexchange.com/questions/31766/unable-to-see-anything-after-importing-obj-file

Sometimes when a 3d model is exported then imported, it can be imported really far away and/or really small. Its origin may be displaced. What you can do is select the object and then in the top left go to 3d cursor so you are moving the 3d cursor. Then move the 3d cursor to a place were you can see. Then select the move option at the top left and select the object in the heirarchy. then right click in the 3d view port and select: set origin> Geometry to origin. The object should be at the cursor. If you cant see it still, try scaling it up as much as possible. Hope this helps.


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Bone matrix assignment behaviour change in Blender 2.80
I am trying to port an armature importer add-on from Blender 2.79 to Blender 2.8x.
After the bone is being created the bone matrix is set.
But the assignment of the bone matrix has a different behaviour in Blender 2.82a compared to the older Blender 2.79b.
I created a small script that works for both Blender versions to reproduce this behaviour:
import bpy
from mathutils import *

def new_armature(name: str) -> bpy.types.Object:
    armature = bpy.data.armatures.new(name)
    obj = bpy.data.objects.new(name, armature)

    if bpy.app.version[1] >= 80:
        bpy.context.scene.collection.objects.link(obj)
        bpy.context.view_layer.objects.active = obj
    else:
        bpy.context.scene.objects.link(obj)
        bpy.context.scene.objects.active = obj

    return obj

obj = new_armature('human')
armature = obj.data

bpy.ops.object.mode_set(mode='EDIT')

new_bone = armature.edit_bones.new('Bone.000')

new_bone.head = Vector([0, 0, 0])
new_bone.tail = Vector([1, 0, 0])

bone_matrix = Matrix(([0,0,1,0],[0,-1,0,-6],[-1,0,0,6],[0,0,0,1]))
print("bone_matrix:\n", bone_matrix)

new_bone.matrix = bone_matrix
print("new_bone.matrix:\n", new_bone.matrix)

Running that script in Blender 2.79b and Blender 2.82a gives me the following outputs:
user@desktop:~/workspace/blender$ blender2.79b --python test2.py --background
Read prefs: /home/user/.config/blender/2.79/config/userpref.blend
found bundled python: /opt/blender/2.79b/2.79/python
bone_matrix:
 <Matrix 4x4 ( 0.0000,  0.0000, 1.0000,  0.0000)
            ( 0.0000, -1.0000, 0.0000, -6.0000)
            (-1.0000,  0.0000, 0.0000,  6.0000)
            ( 0.0000,  0.0000, 0.0000,  1.0000)>
new_bone.matrix:
 <Matrix 4x4 (0.0000,  0.0000,  1.0000,  0.0000)
            (0.0000, -1.0000,  0.0000, -6.0000)
            (1.0000,  0.0000, -0.0000,  6.0000)
            (0.0000,  0.0000,  0.0000,  1.0000)>

Blender quit
user@desktop:~/workspace/blender$ blender2.82a --python test2.py --background
Blender 2.82 (sub 7) (hash 375c7dc4caf4 built 2020-03-12 05:30:40)
Read prefs: /home/user/.config/blender/2.82/config/userpref.blend
found bundled python: /opt/blender/2.82a/2.82/python
bone_matrix:
 <Matrix 4x4 ( 0.0000,  0.0000, 1.0000,  0.0000)
            ( 0.0000, -1.0000, 0.0000, -6.0000)
            (-1.0000,  0.0000, 0.0000,  6.0000)
            ( 0.0000,  0.0000, 0.0000,  1.0000)>
new_bone.matrix:
 <Matrix 4x4 (-1.0000,  0.0000, 0.0000,  0.0000)
            ( 0.0000, -1.0000, 0.0000, -6.0000)
            ( 0.0000,  0.0000, 1.0000,  6.0000)
            ( 0.0000,  0.0000, 0.0000,  1.0000)>

Blender quit

As you can see, the new_bone.matrix matrix differes between these versions.
Updating the scene also does not change anything.
Can you give me a hint how to get the Blender 2.79b behaviour in Blender 2.82a?
My platform is Linux with Kubuntu 19.10 x64.

The resultant rotation of both matrices is equivalent.
If we look at the quaternion  rotation of each matrix can get the angular difference
Using 2.90 alpha and tacking following onto script
print("bone_matrix:\n", bone_matrix)
print(bone_matrix.to_euler())
new_bone.matrix = bone_matrix
print("new_bone.matrix:\n", new_bone.matrix)

print(new_bone.matrix.to_euler())

q = bone_matrix.to_quaternion() # M1
q2 = new_bone.matrix.to_quaternion() # M2
print(q, q2)
ad = q.rotation_difference(q2)

axis, angle = ad.to_axis_angle()
from math import degrees

print("Rotate M1", degrees(angle), "about axis", axis, "to match M2")

Output
bone_matrix:
 <Matrix 4x4 ( 0.0000,  0.0000, 1.0000,  0.0000)
            ( 0.0000, -1.0000, 0.0000, -6.0000)
            (-1.0000,  0.0000, 0.0000,  6.0000)
            ( 0.0000,  0.0000, 0.0000,  1.0000)>
<Euler (x=-3.1416, y=1.5708, z=0.0000), order='XYZ'>
new_bone.matrix:
 <Matrix 4x4 (-1.0000,  0.0000, 0.0000,  0.0000)
            ( 0.0000, -1.0000, 0.0000, -6.0000)
            ( 0.0000,  0.0000, 1.0000,  6.0000)
            ( 0.0000,  0.0000, 0.0000,  1.0000)>
<Euler (x=0.0000, y=-0.0000, z=3.1416), order='XYZ'>
<Quaternion (w=0.0000, x=0.0000, y=0.0000, z=1.0000)>
<Quaternion (w=0.0000, x=0.0000, y=0.0000, z=1.0000)>

Rotate M1 0.0 about axis <Vector (0.0000, 1.0000, 0.0000)> to match M2

The quaternions are same.
Looking at the Euler angles will notice that the end results (in degrees)
Euler((360, 180, 0))

is equivalent to
Euler((0, 0, 360))

This is often seen as gimbal lock in Eulers were two eqivalent rotation matrices flip flop.
Would favour the more well formed nature of M2 with values on the principle diagonal.
Suggestion, using quaternion rotation for bones makes sure they have a singular value per rotation.

There is bone_matrix in left-handed system. It makes no sense to consider the differences between versions when the wrong parameters are inputted into Blender.
bone_matrix in left-handed system:
 <Matrix 4x4 ( 0.0000,  0.0000, 1.0000,  0.0000)
            ( 0.0000, -1.0000, 0.0000, -6.0000)
            (-1.0000,  0.0000, 0.0000,  6.0000)
            ( 0.0000,  0.0000, 0.0000,  1.0000)>

bone_matrix in right-handed system:
 <Matrix 4x4 ( 0.0000,  0.0000, 1.0000,  0.0000)
            ( 0.0000, -1.0000, 0.0000, -6.0000)
            ( 1.0000,  0.0000, 0.0000,  6.0000)
            ( 0.0000,  0.0000, 0.0000,  1.0000)>

Thanks for your answer!
It's possible that the matrix is wrong. The origin matrix targeted directX, so left-handed system. Maybe there is something wrong with the matrix conversion from directX coordinate system to blender's coordinate system.
Do you have a solution how to convert a matrix from directx coordinate system to blender coordinate system?


text:
Why is my object rotating oddly?
https://youtu.be/ISEo-8k-6gg
I'm trying to animate a treasure chest, so I moved the origin to an edge, and now I cant rotate it properly. I know you can do this, but I don't know how I might've messed it up.

Please provide some context and explanation, don't just post a link to a video While videos and images are helpful they should not be the only source of information, add some description of the issue along with some screenshots.

Before adding keyframes you need to apply the rotation using CtrlA.
You are experiencing a gimbal lock, which happens when two rotation axes coincide causing a loss of rotational freedom- in this case, the X and Z axes. This is because you have set the Y rotation value to 90, so applying it should solve the issue.
More on gimbal lock: https://en.wikipedia.org/wiki/Gimbal_lock

This is Euler bad interpolation. You can easily fix this: Align your chest with the global orientation, parent it to an empty, rotate the empty so that the whole chest is orientated the way you want in the 3D scene, then keyframe the opening. Now that the chest is parented to the empty, its new global orientation is relative to the empty, not the world.

This is called a gimbal lock. It appears with Euler rotation. Blender default is XYZ Euler. You need to use quaternion rotation. These can be chosen from pop-up menu under rotation angles.
Quaternion rotation is a bit more difficult but it is worth learning. You need it if you want to rotate something around more than one axis.


text:
Unwanted fluid simulation clumping
I'm running this fluid simulation at a small scale (real-world scale) and I find that the water particles clump together into balls?
I can't seem to find the setting to make it more like a constant flow and would love a hint on what to tweak to achieve the goal?
The image below shows the unwanted status quo.

try increasing the resolution of the domain or minimum timesteps

Thanks, I've been tweaking these numbers, but maybe I haven't raised them high enough for the desired effect. I'll report back once I've run the sim a few more times.

Thanks to the comments left on the question, I was able to solve this issue by increasing the resolution divisions on the domain.
Originally I was running it at +/-128, but had to bring it up to 256, 320, and even 512 until I started seeing the results I was hoping for.

You might also try playing with reducing particle radius.  Sometimes various combinations can save on simulation time.


text:
Rendered image does not show transparency or lighting
I have exactly 1 day experience of Blender so this is sure to be something really basic. I have created a scene with a light and a single cube with translucent material, when I look at the scene through the camera in the Blender UI I see this, which is what I would expect:

but when I look in the rendered PNG file I see this:

i.e. no shading or transparency. I just want the rendered image to match what I see in Blender.
One thing to note - I need to be able to render the image using code only, so telling me which menu/button to use within the UI won't help me.
My script is as follows:
import bpy
import mathutils, math

scene = bpy.context.scene

# Lights
light_data = bpy.data.lights.new('light', type='POINT')
light = bpy.data.objects.new('light', light_data)
light.location = mathutils.Vector((5,5,5))
bpy.context.collection.objects.link(light)

# Camera
cam_data = bpy.data.cameras.new('camera')
cam = bpy.data.objects.new('camera', cam_data)
bpy.context.collection.objects.link(cam)
scene.camera = cam
cam.location = mathutils.Vector((5, -5, 5))
cam.rotation_euler = (1, -0.5, 1)

# Action
mat = bpy.data.materials.new(name='mat')
mat.diffuse_color = [1, 1, 0, 0.5]
bpy.ops.mesh.primitive_cube_add()
cube = bpy.context.object

cube.data.materials.append(mat)

scene.render.image_settings.file_format = 'PNG'
scene.render.filepath = "cube.png"
bpy.ops.render.render(write_still = 1)

I found the answer to this with some help from r/blenderhelp
Adding the following line made the cube render with the correct transparency
bpy.context.scene.render.engine = 'BLENDER_WORKBENCH'

For transparency make sure you have "Transparent" checked on:

And for the shadows - it seems you don't have a light source next to the cube, if there's no light there can be no shadows, add a light by pressing SHIFT + A and clicking on light, I'd recommend getting a sun so everything is lit and you can check if there are shadows.

thanks for your answer, changing the light source type of 'SUN' fixed the illumination problem but the transparency setting had no effect.


text:
How to Generate a Collection of Instances in Geometry Nodes?
I would like a mix of different branches and not just the same instance. I know that it is possible with objects that already exist in a collection in the outliner but is it possible to create a collection dynamically containing a list of instances that have been randomly/dynamically generated with Geometry Nodes like the one i boxed in red below?

Put all types into Geometry to Instance node, And click on Pick Instance in Instance on Points node


text:
How to get a shader node's field name using data path?
In this post Is it possible to get the property name from a data_path? I am able to get the field names from RMB > Copy Data Path in all object properties as well as their modifier name fields using this code:
def get_property_name(data_path) -> str:
    s = data_path
    i = s.find('.')
    data_path_1 = ""
    data_path_2 = data_path
    if i > 0:
        ri = s.rindex('.')
        data_path_1 = '.' + s[0:ri]
        data_path_2 = s[ri+1:len(s)]
    data_block = "bpy.context.object"
    data = eval(data_block + data_path_1)
    return data.rna_type.properties[data_path_2].name if hasattr(data, data_path_2) else ''

Unfortunately if you change the line data_block = "bpy.context.object" with, for example the default material of the default cube named Material value to line data_block = 'bpy.data.materials["Material"]' and then call the function with any node field's data path, it will always return the same name Default Value. For example, the data path for the node field Subsurface Radius is node_tree.nodes["Principled BSDF"].inputs[2].default_value and will return the name Default Value instead of Subsurface Radius as will all the other node fields. Is there any other way how we can retrieve the node field name?

This method here will work for all node trees including Shader Nodes, Compositor Nodes, and Geometry Nodes.
material = bpy.data.materials['Material']
path = 'node_tree.nodes["Principled BSDF"].inputs[2].default_value'
material.path_resolve(path, False).data.name  # => Subsurface Radius

excellent!! thank you soo much!

there are times i pass an incorrect path and path_resolve throws an error, is there some check i can make before calling this function? something like if is_path_resolveable(): path_resolve()?

Use a try and catch the error.

hmmm yeah but i tried to avoid that as it is expensive XD well if there's no other way, then i'll use a try/catch :) thanks!

Use Full Data Path instead of Data Path
import bpy

def get_property_name_from_data_path(data_path) -> str:
    ''' Get the name of a property.

    data_path (str) - Data path from which to take data and property.
    return (str) - The name of the property.
    '''
    data = eval('.'.join(data_path.split('.')[:-1]))
    property = data_path.split('.')[-1]
    if property == 'default_value':
        return data.name

    return data.rna_type.properties[property].name if hasattr(data, property) else ''

name = get_property_name_from_data_path('bpy.data.materials["Material"].node_tree.nodes["Principled BSDF"].inputs[2].default_value')

print(name)

thank you. unfortunately, i can't use full data path because i'm depending on the keying_set feature. when i do Add to Keying Set it will only put the relative path. So i only have that value to deal with.

Ok, but this will work on every property.

but yeah this is also really cool it can get the name for every property for all node trees! great job and thank you very much!


text:
Changes in Python text editor are executed immediately
I have a simple script that moves the cube. It seems that any change I make in the script is executed immediately (the scene changes) even if the script is not saved yet!
I do not think this is intended behavior.
import bpy
import mathutils

print('running')
Cube = bpy.data.objects["Cube"]
Cube.delta_location = mathutils.Vector((0, 0, 0))
for i in range (0,500):
    Cube.delta_location += mathutils.Vector((.01, .01, .01))

E.g. if I change the 500 in the range to 100 the cube moves to the origin at once...
BTW, this is on Linux Mint.

Turn off live edit in the text menu https://docs.blender.org/manual/en/latest/editors/text_editor.html#text-menu

Yes, that was it. Thanks!


text:
Damaged baking result
Im using blender 2.82 with cycles renderer and im trying to export object to unity (as fbx). Very simple one:

My problem is that after baking colors are damaged. Some areas are black (even after recalculation of normals).
This is my shader configuration:

After creating a jpg file for uv, recalculation of normals, UV Unwrap, F3->Smart UV Project->setting borders to 0.03

im trying to bake with configuration bellow:

But the result is a disaster:

What im missing?
Thanks!!!

you are missing the shader after the texture...
and i recommend to change flat to box in this case for better result
good luck (y)

Im starting my adventure :). Thanks very much 4 help !!!!


text:
Multiple similar functions mapped to one hotkey?
First time posting to these forums. I am in the process of trying to learn Blender having come from a Max, then Maya centric workflow. I was wondering how difficult it would be to map a series of similar functions to a single key that can then cycle through them?
I tend to want to have as few hotkeys to remember as possible and have found that this was a good way to go about it. As an example, in Maya, I have one hotkey that cycles through transform modes, and another that handles axis constraints. In theory, I could also create one that cycles through subobject modes.
Thanks.

I've never used Maya or Max so I don't exactly understand what you need. Blender has context  menus, accessible pressing the right mouse button, the meny change according to the editor and tools selected. And there is also a Dynamic context menu addon: https://docs.blender.org/manual/en/latest/addons/interface/context_menu.html?highlight=context%20menu

Blender has a quick favorites menu, hotkey = q. To add operations to the quick favorites menu, simply right click on the operation and choose add to quick favorites.
For example, let's say I want the add mesh operation to be in my quick favorites menu:
Now when I hit q this is what I see.


text:
How do i add in vertex on the surface area?

I control right click but it sets where my cursor at instead of my model surface area. Is there anyway to add vertex points without the need to use edge?

Did you try enabling the SNAP (to plane) feature?

Sorry, could you be a bit more specific as to what you're trying to do? Are you simply trying to add a vertex to a face?


text:
i connected the two vertex but now i can't seem to select the other face on the top half?

why? it selected whole of the face instead. I just want that top half section. This is after I connected the two vertex

You must have connected the 2 vertices with F (fill), which won't separate the face in 2 separate faces, but just create an edge between the 2 vertices over the existing face. If you want to connect the 2 vertices in order to cut face in 2 parts, choose J (join).

You can use the Knife Tool (K) if you want to actually cut a face from a vertex to the other. It seems like you just made an edge between those two opposite vertices on top of the existing face. Hope this helps.


text:
Trouble with difference Boolean
So im having an issue with boolean. I have a screenshot here and ive searched everywhere i could but i really cannot even explain it properly enough to find a solution. If yall need more information i will provide what i can, i just have never seen this before.
The cylinder is to difference from the back of the model here, but the left side of the model is clipping to the right side of the cylinder. If i make the overlap threshold .025, it no longer shows this clipping but when hitting apply, it does not even create the difference inside of the model. If i make the cylinder smaller, the pulling section dissapears, but then still after hitting apply, it does not create the actual difference. I was able to do this on a different part of the body and it turned out fine, but doing this part and the same thing to the body of the model im getting this weird magnet style clipping.

This next image i took the face off the cylinder and youre able to see how its melding?

This image here i removed the back of the model so it is hollow and it still pulls as i thought maybe it was how i closed the object off

Please let me know if any more detail is needed, i am currently at a loss and too tired to google any longer.

did you try disable the armature modifier? if so probably fastest way is to upload simplified blend that still generates this issue https://blend-exchange.giantcowfilms.com or check this A https://blender.stackexchange.com/a/34787/2214 especially non-manifold section or here https://docs.blender.org/manual/en/latest/modeling/modifiers/generate/booleans.html

@vklidu Detaching the amarture to place the boolean worked perfectly. Ill have to remember that for now on. Thank you!


text:
How can i make color animation (as a sci fi wall)
I am new to Blender.
I made a wall but unfortunately i can't make the background material

Hello and welcome :). Congratulations on your wall. I can see some geometric background pattern right there. What exactly can't you make?

i want to make a material for the background plane

Again, what exactly? Absolute unclear what you're asking for. What in your image you call background plane? Mark it red or something, for now we can't really help...


text:
Alpha over not working properly for me
I'm having trouble with this project I've been working on. I've been directly following this tutorial youtube.com/watch?v=9Q8PwcDzb8Y , however at 43:33 when he uses an alpha over, I'm not getting the same results. The glare works before I add alpha over, but after I add it, it disappears.
This is what mine looks like
https://i.sstatic.net/63iuf.jpg

Can you take a closeup screenshot of your node tree? That is way too small to make out.

How to upload an image to a post


text:
Bone Drivers to Copy Rotation
Can I set up a Driver for the bone on the left to slightly copy the rotation of the selected one when rotating clockwise on its Z axis, and to copy the rotation with higher influence when rotated counter clockwise on its Z axis?

you could do this by putting a simple condition in your driver's code block:
zrot / 2 if zrot < 0 else zrot * 5

which gives this:

⚠ Note that you can just map the range(-180,180) to something else. it means that if you rotate counterclockwise when zRotation is currently greater than zero this doesn't work. if that's what you really need you can animate your reference bones and using f-curves you can do the rest.

Somewhat related https://blender.stackexchange.com/questions/164765/rotation-driver-skipping-backwards-after-90-degrees  IMO will need to keep the value of the previous frame eg going from 90 to 100 or 80 on next frame will both be considered > 0.  See the slow value example in Text Edtor > Python > Templates > Driver Functions

@batFINGER thanks but blender doesn't store added functions. I wanted to ask this problem before but I forgot. whats your opinion about it.

@batFINGER instead of using addons is there a way to store (or run before load) these kind of functions in blender?

put them in a text block with py extension, add the methods to driver namepace in register method. Check the register checkbox in text editor. Text > Register save to startup file.  Requires Auto run python scripts to be set in prefs too.

thanks so much!


text:
Modify Reflection Color in EEVEE
I'm currently working on a scene with screen space reflections (using light probes) in EEVEE. I would love to change the color of the reflection only (specifically to black&white but ideally with more room to modify it).
So for example, a red cube would appear black&white in a reflecting surface.
Is this possible? It seems like a pretty easy task but all my attempted solutions so far have failed.

I tried using the light path node on the cube's shader but most attributes don't work in EEVEE (eg IsReflectionRay).
I tried to convert the glossy shader of the mirror to RGB and set it's saturation to zero but it removes all the reflections altogether (it says this in the documentation too).

Could anybody help me with this? Thanks!

"Is Reflection Ray" works for Eevee (one of the few that works from "Light Path").

If some other settings were to be checked:

Thank you!!!
It was actually just the reflection pane that I had setup incorrectly + I did not know i would be able to see a reflection of the cube without the lightprobe (which then gave me the IsReflectionRay of zero for both).
Also it did not help that the documentation does still label it as "Cycles only".


text:
Why are the distributed point objects not aligning to the normals of the faces?
I'm following this cool YouTube Burger Tutorial but unfortunately the Geometry Nodes part is not applicable in the latest versions of Blender so I had to do some adjustments but I'm not sure why the distributed objects don't align to the normals of the faces. I think I need to use a Capture Attribute node but I'm at a loss on how I should use it in my setup.

They align though to the normals if I mute the Random Value node but then they all face towards the center.

First, you don't actually need to use Align Euler to Vector in this case, since you already have the Rotation socket available. Rotation there is the direction of the points as aligned to the normals of the faces they're distributed on, so you can link that directly. Not every node will give you that information though, in those cases you might need to capture or sample the face normals and use that to align your vectors.
I would do any extra random rotations on top of that with a separate Rotate Instances node:


text:
Modeling Steelbeams and
I am doing all tutorials and now I want to start drawing steel beams and wall elements. Now I want to ask here some people with more experience about how to make them. Which method is the best for something like that.


text:
Correct mistakenly changing mouse select to left button
When I installed 2.81 I mistakenly chose select with left button. I use the mouse with my left hand and actually want to select with right button. My Preferences>Input does not have a provision to change this. My download is named /blender-2.81a-linux-glibc217-x86_64. Is there a work around?
(I have two previous versions of Blender installed and when I used them I selected with the left button.)

Head over to the Keymap tab and you'll find the select options under Preferences


text:
I want to break a wall with a ball in real life
I am new to visual effects and to blender, of course. So I would appreciate it if anyone could help me.
So basically I recorded myself throwing a ball to a wall. When the ball hits the wall I want the wall to break off(fall off).
Here is a gif!

I was able to motion track the video and created an object to where the wall should be in 3D space.

Now my problem is I don't know how to make the object look like the wall.
I don't know how to make its texture look like the texture on the wall and then drop off.
Can anyone help me?


text:
When I select a material in doesn't appear in the Compositing Editor
Even though I am using the Cycles render engine and I have also ticked the use nodes box,
no nodes appear when I select a material. Also I cant find any shader in the node editor!

These nodes appeared when I opened the editor. Can anyone see whats the problem? I am new to blender!

I am stupid... Thanks!

Concept misunderstanding ...  I say :)

Material appears in Shader editor. In Compositor appears render.
If you dont see nodes in Shader editor, go to View > View All


text:
What's the best book to learn blender?
Just as the title says, I am looking for beginner's book for blender. Specifically I want to learn special effects and 3D models.
Anyone got any suggestions?

Well...I don't know of any books I'd recommend, but I can give you a few suggestions when it comes to digital content.
A good place to start is with BlenderGuru's Donut Tutorial Series. That'll help you get a good start with Blender (learning the UI, basic modelling, texturing, rendering etc).
If you're willing to spend a bit of money, I've found the Hard Surface Modelling Tutorial Series to be a fantastic way to quickly progress from a beginner level to an intermediate one (in terms of modelling). There are a few caveats, as it has been recorded with the 2.79 UI. However, everything that they teach can also be learned while using 2.80+ (I can personally attest to that). They'll teach you the tools that you have at your disposal, many modelling techniques and workflows, not including sculpting, and the theory behind proper shading, good topology etc.
As far as special effects and animating goes, there are plenty of free materials online. Poke around StackExchange and find Q/As that are related to what you want to do. Try to focus on understanding the tools that are presented so that you may apply them elsewhere. Tutorials such as the LazyTutorials by IanHubert can help you in that aspect.
To be honest, where you want to go and what you want to focus on is up to you. To my knowledge, everything that you can learn from paid tutorials can also be learned for free or figured out on your own. What the paid tutorials do is to condense the knowledge down so that you can learn quicker and in a more organized fashion.


text:
Force IK rig to bend knee "Wrong" way?

I've designed this mech's legs so they can fold up when crouched but that left the knee pivot behind the top one so my IK rig bends my leg the wrong way. Can I have my knee behind the "pelvis" and force the knee to bend forward still?
Thank you!

Even in a real world robot, pulling up the foot would lead to the "incorrect" way. You have to tell him if you want walk or fold. I think the better way is to use IK for walking (where it's useful) and FK for folding (which is simple), so it would be better to choose a forward bending as rest pose.

It turns out I was overthinking this problem. I simply had to bend the knees before I rig it.

Then it doesn't fold-- same problem as before, just in reverse.  You need to control the direction of the bend by bending the calf in pose mode.


text:
Can't select bones in pose mode
I'm new here so I don't know if I'm making this question in the right place, but I'm having an issue with bones in Pose mode and would be so thankful if anyone could help.
I can select them without any trouble in Edit and Object mode, but whenever I move to Pose mode I can't select them anymore. I could select them on the Outliner, but that isn't very practical nor intuitive.
Also, whenever I do select the intended bone, I get no outlines, just a very faint coloring on the object. That gets really confusing when I'm using bendy bone segments, as I can't tell whether they are there or not in side and front views.
I'm on Blender 2.82.7
I tried uninstalling and reinstalling the latest version, updating my drivers, but nothing has worked so far.
Sumarized:

I can't select individual bones in pose mode unless it's from the outliner
Whenever I can select the bones, I can't see their outlines

Happened to me as well. Probably a bug. I cant use select or box select but laso and circle select works, its annoying as hell.

I am experiencing the same issue. My workaround for now is to use shift-select and box select.

I had this exact same problem when trying to bring an armature from 2.8 into 2.79, and I found a solution that worked in that case, so maybe it will work for you as well. Try the following:
Create a new additional armature with a single bone in your project file. Then in Object mode, select your problematic armature (the one you can't select bones from in pose mode), shift-select your new single bone armature, and join the two (ctrl-j).
When I did this I was able to select all of my original bones in pose mode again.

Hey waruta! It doesn't seem to be working, but it got me thinking that maybe the problem was in the file itself. I appended the model and armature onto a new file and so far I can select the bones from pose mode (!!!) though it has worked briefly in the past and then stopped working. Hoping that won't happen again.
Still no outlines, but this is a huge improvement! Thanks a lot for the idea and trying to help!

I've got the same problem and realized that it was because a saved the file with armature in Pose mode. If I save in object mode, all goes prety well. Must be a bug,to be solved in 2.83.

I was experiencing some of these symptoms and jumped to the conclusion that I was experiencing a potential bug; later, I found that in my case it was due to a simpler cause -- and giving a simpler solution.  If you are experiencing this issue, it can help to rule out the simpler cause first.
In my case, the symptoms I was experiencing were due to my accidentally toggling Tweak/Cursor mode.
The following is demonstrated using version 2.91.0
Suppose your workspace appears like the following:

First open up the menu that exposes the Tweak/Cursor mode setting:

In my case, I achieved this by dragging from the left edge of the workspace window.
Opening it a bit further helps illustrate it better:

Here is what it looks like for me when I hover over the Tweak mode setting, showing the shortcut that enters me into Tweak mode.

And here is what that looks like when hovering over the Cursor mode setting:

When I'm stepping through an animation using Shift-Space it is easy for me to accidentally toggle into Cursor mode, for which the shortcut is Space-Space.
When I'm in Cursor mode, I can select the first bone using Shift-Select but not Select.  When I'm in Tweak mode, I can select the first bone using Select.


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Why wont curve modifier work across whole mesh? i have added loop cuts as well

Curve Modifier not working on whole mesh
I am making a tire for a car as you can see in the image below, but the curve modifier is only affecting one half of the mesh, please advise why this is happening.
I have tried extruding and nothing happened, scaling does not show any affect either.
Thanks

Make sure that your curve has been looped (cyclic).
Enter edit mode, select any point on the curve and press Alt + C (Toggle cyclic). If curve become cyclic, the curve modifier will deform
the object using curve at any possible position.

Thanks! ill try this

@Amogh don't forget to mark the answer as correct then