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Regular glass or transparent glass material not exporting with .glb or .gltf for three.js website
I'm designing some cool glass spheres, similar to marbles, in Blender. Then, I want to export the model as a .glb and use it in my web app with three.js. I'm importing them into the browser using three.js.
I've used blender quite a bit for making simple 3d logos and stuff, and this method always works great. However, I'm having trouble getting the glass material to export with the model. Instead, it always just exports with a transparent sphere with zero material or texture.
Here's what it looks like in blender:

Here's what it looks like in the browser:

I'm using some simple techniques to achieve the glass effect.

Set transmission to 1
Set roughness to 0
Set IOR to 1.7

Other than that, I've tried changing the material settings Blend Mode to "Alpha blend" to try and get more of a transparent glass effect. It looks nice, but none of it exports with the model.
When I export, I'm including everything necessary to my knowledge:

Here's a copy of the .blender project file in case anyone would like to take a closer look.
Any help on this would be greatly appreciated! I'm pretty surface level with Blender.

https://blender.stackexchange.com/questions/57531/fbx-export-why-there-are-no-materials-or-textures/

@DuarteFarrajotaRamos Thanks, that's a very insightful read. However, according to this sentence, it looks like I may be able to do this using gltf/glb: One notable exception to all this is the glTF file format, which as of version 2.0 glTF does support some material definitions based on a metallic-roughness shading model in its specs

Okay... I'm seeing this is still very limited... Hm. I'll need to research further and check for a workaround.

You're correct to use the "transmission" setting instead of alpha blending for glass here.  Several recent releases of Blender will export transmission to glTF, since 2.9x or so, certainly all of the 3.x releases will do it.

Here's what it looks like in the browser:

The problem here is you've given it a boring blue background, and all that fancy glass has very little to reflect or interact with.  You need to give your 3D app an IBL (Image-Based Lighting) texture, to provide a textured environment for your models to adapt to.
You may also want to try placing a background object of some kind in the scene.  For example the Dragon Attenuation test model includes an opaque checkerboard cloth behind the dragon, to better portray what happens to light on the way through.

One last note, current stable versions of Blender (up through 3.2.0) do not yet export "volumetric" glTF like the dragon has, just "thin-walled" transmission (as if your marble was merely a glass bubble, hollow inside).  This is being worked on for Blender 3.3.0, but is still in testing.  For now I recommend focusing on getting the thin-walled transmission working first before moving on to enabling volumetrics.

That's interesting... Because I actually tried adding a plane to the model. And it showed the red color when I did that. However, it didn't show any of the nice reflected textures that makes the "glass" effect. It was basically just a red sphere with some transparency.
So, correct me if I'm wrong. The problem is that the model needs something more busy than a gray plain or blue background to create "reflections"... I'll play around with this idea and see what happens. Thanks!


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How to keep the left side of my model Mirror modifier
I have modeled a low poly human figure with the mirror modifier. I then rigged it and when I move the right side the left side is mirroring the right side. when i turn off the mirror modifier the left side of the model disappears. Im sure its an easy fix im just not sure how to fix it.

You'll need to apply the modifier before you can move the two sides individually.

You need to put the Armature modifier under the Mirror, but as John Eason says it may be more convenient to apply the Mirror

source: Stack Exchange

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

sort: votes


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Animation render problems
I have an animation with a layer for the background and a layer for the armature. Buy when i render animation, the character and armature appears gray.any ideas?

Are you using post-processing Compositor nodes?  If yes: show a screen-shot.  Or if willing, include your blend file via https://blend-exchange.com/

dunno about the nodes since they seem really complicated so i never touch them. heres the file any ways https://blend-exchange.com/b/ZGreRsks

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


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Geometry nodes - Why is "mesh to curve" extending the selection of nodes?
I'm trying to thicken a loop automatically with geo nodes.
I created a vertex group from the target loop and uses it as input within geometry nodes.
But the "mesh to curve" node creates curves between nodes that do not belong to the selection, hence resulting in a rake more than a hoop.
Is this expected behaviour or did I miss something?

"Why" has been answered well IMO, but a different workaround to the problem is input->separate geometry->mesh to curve, which leaves you with only the edges you want going into the curve.

You would simply have to apply the vertex group to the points first with Capture Attribute, and then use that as the selection for Mesh to Curve:

Here I use the node Named Attribute (Blender 3.2) for the vertex group, but of course you can also do this with a Group Input (Blender 3.0).

A short (simplified) explanation:
It has to do with "Domains".
A vertex group defines points, but Mesh to Curve works based on edges.
When you process a vertex group in Geometry Nodes, this selection is interpolated to all other domains, which also selects adjacent edges.
So all edges that have a point in this vertex group will be converted by the node Mesh to Curve.
With Capture Attribute, however, the selection is explicitly applied only to the points domain and then only edges are selected that actually have both points in this vertex group.

Amazing. I hadn't realized that a selection of vertices is not just a selection of vertices in geo nodes but that it can be specified what attributes are to be used. :)

@JagJB Values that are not explicitly restricted to a particular domain are interpolated ...I have attached an attempt at a brief explanation of this.

It is because vertex group has a vector domain, while you want to get edges. This node setup solves the problem:

Thank you  so much. Both answers are pertinent and converge to the same solution. I gave credits to both ;)

Another way of thinking about it?

This cluster selects as expected.
Vertex groups are Floats, (however you think you've stored them) .. and the cast to Boolean interprets everything above 0 as True.
So edges interpolated to 0.5 (1 at one end and 0 at the other) cast to True, but can be explicitly evaluated as False.

Very interesting perspective! Despite all expertise, in this way I have not looked at it at all. As so often, thank you for expanding my horizons!

@quellenform   .. and vice-versa .. yours and Cranitsz' method took me by surprise ..:)

Yes of course, it's a float as you can have weight factors in a node group! I hadn't realized I was implicitely converting values when connecting the blocks.
Thanks for the explanation!


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Design dyson roller with unknown broken area
I am new in Blender, and doing hard to learn that. I was trying to made a Dyson vacuum cleaner parts by Blender and I made it, but the final model has a problem that I don't know why and how to fix it.
This is what it looks like in the object mode, I saw this problem after I have add solidity and subdivision on it:

This is the rendered image with clear broken area:

This is what it looks like in edit mode and without solidity and subdivision:

In my mind I haven't made any N-gon in these area, so I don't know why it happens, could anyone tell me the reason of that and how should I avoid on next time?
Here is the source file:
Blender File
Thank you very much for reading this thread.

Hello :). You have flipped faces, you need to recalculate normals. There are also double verts and other non-manifold geometry.

Related: Inaccurate shading on object

Hi, thank you for your reply! But I don't understand why I have flipped faces, I almost did it face by face myself, and double vertices also. Could you please some references that I can know more about that? thank you once again

Hey :). Flipped faces just happen during modeling, there can be many reasons. The same with double verts. But neither are big deal and easy to deal with :). Related: What is Non-Manifold geometry

Thank you so much for such kind of help! Thank you!

No problem :). Good luck on your Blender journey :).

After viewing your model, here's what I did:
#select the meshes then ctrl+A to apply all transformation.
#select the object go to edit mode and select all the vertex by pressing A once or twice. And then shift+N to recalculate normals.
Your mesh had some flipped normals which caused the issue you marked.  Here's the File after applying the fixes I mentioned.

thank you very much for your help! I really need to search the meaning of these actions then! thank you!


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Is there a way to get the shrinkwrap constraint to move the target to the object rather than the reverse?
In the image below there's a cuboid that has a shrinkwrap constraint to a distorted cylinder. As I rotate the distorted cylinder in the x-axis, the cuboid moves up and down following the uneven surface of the cylinder.
What I want is to flip this over and have the distored cylinder move up and down as it rotates over the stationary cuboid. That is, I want the same shrinkwrap constraint to move the target instead of the object. Does this make sense? Is there another way to go about it?

Can’t you just have the shrinkwrap constraint on the other object - ie, shrinkwrap the distorted cylinder to the cuboid rather than the cuboid to the distorted cylinder.

This probably won't be the most efficient answer, because I don't really understand what end result you are trying to achieve, but you can add something called a driver.
Drivers let you "drive" values based on other values. So you could have rotation of one object drive the global position (or any other value) of another.


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I am editing a model to be 3D printed, how to merge two faces in a same object?
I have a model like this:

Due to overhang issue I would like it modified from this:

To this (edited in GIMP):

My idea is to:

Extrude the leftmost and the bottommost faces until they are intersected (done, as you can see in the two bottommost screenshot above)
Join two faces (I still don't know how to do this!)
From the joined edges fill them with faces
Delete unnecessary faces and edges

From Google search I came with Intersect (Knife) and Intersect (Boolean). I have selected the two faces, then choose either of them, and my model was gone from Blender.
So... how can I join two (or more) intersected faces in Blender, within the same object?

if i know your question, you can use boolean union to merge two mesh part into one,
but you can simply join the object (ctrl-J) this is non-destructive way the mesh will sliced as intended on slicer as long both mesh is manifold

If your mesh is not pathological in some other way, (duplicate vertices, inconsistent normals, or somesuch), Intersect Knife should work, to create an edge at the intersection of your faces.
However, if the angles are convenient, then you can avoid the calculation of intersections by just snapping the ends of your faces together.
With Snap set to 'To: Vertex', and 'With: Active', GZ the bottom edge of the vertical face to the horizontal one, and then GX, vice-versa:

If you have Automerge switched on in Header > Options, you're done.
Or you can manually weld: M Merge > By Distance.


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Foliage wind effect with hair particles + turbulence
I've been working on this scene trying to create a smooth wind effect using hair particles + turbulence effector.
GIF HERE

I've tried a lot of different settings but there's always some individual plants rotating on a weird way, it breaks the smoothness of the effect.
How can I achive this? is it possible with geometry nodes?
This is how I'm trying to do it:
Create a plane, subdivide it, weight painted desired area for the plants, create a particle system, change it to hair, set render as object, select instance object (plant), add turbulence effector, animate it, play with the settings.
I'm not sure if I need to add a constraint to the original object or my turbulence settings are not good.
Please help, Thanks!

Turbulence is not like wind, really. Maybe try a wind field, but set it to the “apbsorbed by objects” thingy? That would be most realistic. If all else fails, use an animated wave texture instead to entirely fake the motion.


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Use Two Circles to Bend a Cylinder's Geometry in an Animation?
Is it possible to control the shape of a cylindrical cone using two bezier circles? (See GIF)
Currently, I am using two hook modifiers that connect all of the vertices of the cylinder to two separate empties. These empties are then parented to the bezier circles at the top and bottom of the form. Unfortunately, the cylinder position seems to drift away from the bezier circles as their position moves. I've tried to adjust the strength and fall off curves of hooks with no success.
Has anyone tried to create something similar before? What might be a better approach to achieve the desired effect?

This looks like a classic Bendy Bones application. There's a very fine short tutorial here. Maybe a proper rigger can express that as an answer.

I think the issue is parenting, just use the hooks alone. Simultaneous parenting and hooks may be adding commulative transforms


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Blender Object jitters/shaking while animated along path
I'm using Blender 2.9 and having the classic object jittering/shaking issue when it follows a path (Bezier Circle). It may be a floating point issue.
I saw a solution, which suggests to parent the object to  world Origin Object. But I'm not sure what it means...
Any suggestions? It'd be highly appreciated.

maybe your curve doesn't have enough resolution?

I think that I know the answer, but what would be your way of increasing resolution?

select the curve and in the Properties panel > Object Data > Shape > Resolution. What solution have you found?

My shape resolution in U direction  under Shape is set to 64. It was much lower. I tried with 64, I'm not sure if this fixed the issue...

maybe share your file: https://blend-exchange.giantcowfilms.com/

Thank you very much for your  time. I did upload the .blend file. It's a simple Follow Path constraint of a cube to a circle. The cube image jitters/shakes on the path. Not sure why... Appreciate your  help. Here is  the  link  I  was given by the  system:

I've tested and I rendered a video, but I can't see any problem, it seems to work fine to me

Thank you. Not sure what the problem  then.

Was this ever solved? I'm having the same issue when having an object follow a path...


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Cycles rendering is too slow
I have GeForce GTX960M,
RAM: 16 GB,
Intel Core i7-6700HQ 2.60 GHz.
I am rendering simple scenes, from Grant Abbitt, Blender Guru, and the likes' tutorials however, my render takes so much time and it is really discouraging to work with that pace. I can't even preview, I have to wait 10-15 minutes to see if my materials look good or not.
Please, suggest me some solutions. What do I need to do? Upgrading sure will partially solve it but I want to hear solutions other than upgrading, please.
Is the specs that I have really not compatible to learn 3D?

This might help                https://www.youtube.com/watch?v=8gSyEpt4-60

It's all about your hardware and your render settings. I guess your CPU is even faster than your graphics card and Cycles prefers a graphics card...  Have you compared the two already? The render region feature might be helpful in your case: https://docs.blender.org/manual/en/latest/editors/3dview/navigate/regions.html#editors-3dview-navigate-render-region Each scene is different so hard to give any advice in general besides share your scene to compare against and: rendering takes time.


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Blender 2.8 Array modifier rotating individual parts
I am currently trying to model a snake with the array modifier. I want the snake to go around the pole (as displayed in the picture) but I want the red (belly) of the snake to be in contact with the pole (as in this video: https://www.youtube.com/watch?v=wInhCU79_IY&list=WL&index=23&t=465s timestamp: 7:59) . At the moment you can see that it is facing towards the outside of the curve.
Does anyone know how I can fix this?
I have tried to add an empty and use that as my object offset but this makes it so that the different sections of the snake are not connected properly.

Have you tried to tilt the vertices? Select your curve, go in Edit mode, select the vertices you want, and CtrlT to tilt, or use the N panel:

that did it, thank you!


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how to curve cylinder like image below

I want to curve the cylinder so it would be like a rotating ramp

so what's happening on the other side?

what do you mean?

how does the curve continue on the side we don't see? is it a half cylinder?

Make another curve, possible from a curve object converted to mesh, and shrinkwrap/project the top verts in Z axis onto that curve object.  Or, use a knife project operation to cut one mesh with the other, then clean up afterwards.

i am a noob at this, possible to dumbify that?

If you're a noob, then learn the components of what I mentioned.  Learn how to make a curve object.  Learn how to use a knife project.  Learn how use a shrinkwrap modifier.  All of the components of the answer have been answered elsewhere, and when you understand the components of the answer, you'll understand the answer.

Hello :). Something like this? How to model Helix shaped ramp?

Are you looking for something like that?


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Portions of Video Pixelated in iMovie
First post. I’ve been using blender for a month and am now addicted. Made an animation of Suzanne being abducted by a UFO. When I save the video to my computer and iPad, it looks great. But when I import it to iMovie on my iPad, portions of it become pixelated. I can fool around with the iMovie editor and other settings to reduce the pixels sometimes, but they always show up in the same two areas (pictures attached). There's also a lot of lag in iMovie. I’ve tried rendering the scenes from blender in both MPEG 4 and QuickTime containers but the pixels are present in both attempts when imported to iMovie. The file format I'm using is "FFmpeg video" and video codec is "H.264". Thanks for your help.

If the pixels only occur after you import your video into iMovie and not in the rendered file on your computer, then it is probably an issue within iMovie rather than with Blender. You can try exporting the scene as PNGs which you can then string together at 24 per second if you are looking for a different format to use. If the rendered scene looks okay when you play it back on your computer, but pixelated upon import to your iPad, no changes in Blender are likely to fix that. Try asking this question in the "Video Production" or "Apple" stack exchanges and they may be able to help better than we can.

I actually just ran into this problem as well with Final Cut Pro X and the pixelations looked very similar to yours. I fixed it by uploading the Blender outputted .m4v file to an online converter and converted it to .mp4 and it looked great. Final Cut and iMovie seem to have issues decoding the files that Blender outputs.


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Blender CUDA can't find my GPU(MAC)

As I was adjusting my settings I realized that my GPU is not recognized for CUDA at Cycles tab. I tried everything afterward to make it appear- went to Nvidia developers website to download CUDA toolkit(10 version as 11 is not supported on MacOs), reinstall blender, etc.. but it still does not work... Could anyone please help me here?
Thanks for your help!

Have you tried updating your graphics drivers?

Hi, thanks for the reply - I did. I did install CUDA but since I am using Mac OS, the newest version of CUDA (11 I guess?) does not support it... would there be absolutely no solution at all unless I change my graphics card..? I have also thought of buying some sort of external graphics card but not sure if this is the right way to go...


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2d animation armature problems
When i try to pose my armature everything warps and some parts do not move how do i fix this?

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.

i need it to be rigid when i move it and not get all melty

When you parent a GP object to an armature with automatic weight, every deforming bone creates a vertex group in the GP object with the same name.
If you select the GP and go to weight paint mode you can select every vertex group, one by one, and see its weight assignements (blue = 0.0, cyan = some weight, green = 0.5, orange lot of weight, red = 1.0 full weight).
If you want to have i.e. the head rigid, you have to do two things:

in edit mode select all vertices of the head, select the head vertex group, go down to the weight slider, take it to 1.0 and click the "Assign" button.

select all the others vertex groups one by one and click the "Remove" button.

Do the same for the rest of the character parts.

Thank you it worked.


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Why are particles barely visible when rendering transparent background?
When I render a particle system with a black background it looks great. When I render that exact same animation with transparent background to composite it later in Premiere, it is barely visible and loses almost all of its colour. Why does this happen? And is there a way to fix this or work around it? Photos of the same render attached with and without transparent backgrounds.

https://blender.stackexchange.com/questions/260675/glare-alpha-not-saved-to-png-file https://blender.stackexchange.com/questions/222837/blender-does-not-set-the-alpha-channel-correctly https://blender.stackexchange.com/questions/177022/glare-effect-transperancy-problem/177030#177030 https://blender.stackexchange.com/questions/173932/exr-color-difference-to-png


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Textures not aligning with edges
does anyone know how to fix this issue with materials not lining up with the other edge? Ive attached a photo of my problem and I'm sure it's an easy fix but I don't have crazy experience with blender and having trouble with this. It is scaled/uv smart projected only but even with moving the material around in UV editing, it never matches up.

Unwrap again, with some seams where you want to cut the UVs, but not where you want the image to be continued. But even if you cut, you can align the UVs in the UV Editor

can you attach your blend file so we can help fix it https://blend-exchange.com

I tried to upload to blend exchange but I keep getting the error "all uploaded files must be in the blend file format" when the file is a .blend?

@HarryMcKenzie https://drive.google.com/file/d/1lfZUCQbzw3HrzcaaFcT3oiSnWedF7qRr/view?usp=sharing let me know if that works

Texture is missing, you can pack it into the blend file with menu File > External Data > Pack Resources then upload blend file again on https://blend-exchange.com and btw your face normals are pointing outwards, they need to point inwards since your model is on the inside.  Select all faces in Edit Mode and go to menu Mesh > Normals > Recalculate Inside

@HarryMcKenzie ive attached the link to the updated file https://drive.google.com/file/d/1k_cPbfh9Lon0hr65rlUBpQCoo1onAInG/view?usp=sharing


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How can i fill this hole?

Grid fill doesnt seem to work even if I set 7x7.

Hello, could you please share this part of your file so that we can try? https://blend-exchange.com/

You could use this included add on https://blender.stackexchange.com/questions/268098/creating-a-quad-face-with-3-vertices-already-created/268100#268100

I'm guessing the best way is to do it manually by selecting loop pairs and bridging with the appropriate number of cuts to match the adjacent vertices. Then merging those vertices by distance.  You might be able to get close by running grid fill and then smoothing the vertices several times.


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Sculpting issues on a model
When trying to sculpt a model, it seems that none of my brushes are very effective no matter what settings I'm trying. Is this possibly a vertex count issue or am I missing something? I've tried changing strengths, changing brush stroke from spacing to airbrushing, and various different brushes. I do not have a drawing tablet, so I've turned this setting off. It is my first time sculpting so any information would be greatly appreciated.
https://www.dropbox.com/s/jnxobrn8k3lrhik/pug%20assassin%20with%20a%20suit%20and%20shadesrev5%20-%20Copy.blend?dl=0

From what I see ... just press F in Sculpt mode and move a mouse to enlarge brush size (Radius) like 170 px to see effect.

Can you add screenshots of you attempting to use the brush on a model, and what the results are?


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I cant sculpt evenly with missing faces
There are missing faces in edit mode, but only on parts of the inside of the mesh and outside. For example, there may be no vertices or faces in black on the outside of the mesh in a specific area, but when I view the inside, they are there and vice versa. When I sculpt I have to move from one side to the other because it does not allow me to sculpt certain parts on each side.

Sounds as if the normals are inverted on parts of the mesh. Select All in Edit mode and then SHIFT-N to recalculate normals.

Please don't post photos of your screen! You can take screenshots from the Window > Save Screenshot menu in Blender then insert the image that is created directly inot your question. That eliminates any reflections and distortion that may be produced.

Ok thanks for your reply and I apologize, I did shift n to calulate normals and nothing happened until I checked the box next to “inside” in the bottom left of the screen, and the results are what are shown in these screenshots. Do you also know how to fix that line going down his back? I cannot seem to sculpt over it.


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Incorrect Rotation for Imported Vertical Video in *Movie Clip Editor*
Unexpectedly, blender rotates the vertical video shot on my iPhone when I import it into the Movie Clip Editor. How can I rotate the footage in the Movie Clip Editor view so I can clearly work with the tracking options without the footage being rotated the whole time during the editing process?

you can open your movie in video editing and then insert the rotation value 90/-90 as you need it and then just render it out and use the result for your tracking.

Thank you that certainly works, although I hope in the future blender support other aspect ratios correctly! It seems a bit odd that I have to render an entirely. new video with black bars on the side of it to get this working!

You are welcome

Worked like a charm. But why in the first place does Blender import my video as rotated by 90? The video is shot on iPhone and has the dimensions of 1080x1920 (HDR, 60fps, .mov) but Blender imports it as 1920x1080...

Open windows films and tv --> pencil icon --> trim --> trim off a single frame off the end or beginning of your video.

when you open the trimmed version, it should be the right orientation

Your answer uses unnamed program for trimming the video and does not explain how trimming the last video frame will get rid of the rotation metadata in the video file.

@RumenBelev It's not an "unnamed program", the name is "Films & TV" (I admit it the notation is incorrect in the answer, but Google search will nevertheless find it that way) and it is installed with Windows 10. In the US it is called "Movies & TV" other than the rest of the world, as far as I know. But how this changes the rotation... maybe the one answering here does not even know. My simple guess is: since "Films & TV" seems to be able to play it correctly and trimming it forces to save it new replacing the old file, maybe the new file has rotation informations Blender understands.


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Flip Normals with Geometry Nodes
I have geometry being created through geometry nodes and I am am trying to flip the normals on this duplicate geometry. However, it appears that normals are a read only attribute in the geometry nodes. Any ideas on how I can flip normals through geometry nodes?

It's not possible to modify mesh normals at the moment, but it's being talk about : https://devtalk.blender.org/t/geometry-nodes/16108/1519

Has there been any discussion on when those might be implemented?

It's not high priority right now it seems... You can follow the project tasks here : https://developer.blender.org/project/board/121/

You can now use the Flip Faces node.

You can also plug a boolean field into the Selection input to selectively flip faces.
For example :

It is possible to flip normals for any single face.
You just have to do several steps:

Detach selected face from mesh.
Put this face into convex hull.
Delete from convex hull all faces with normals orientation equal to normals orientation of the original face.

I already applied this solution in my answer here:
Is extrude possible in Geometry Nodes?

can you apply this to every face in a mesh?


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Geometry Nodes Separate out Alpha Channel from Vertex Colors
I'm using the RGBA channels of the vertex colors on geometry for various effects but I can't find a way to separate out the alpha channel in geometry nodes. Is there a way to access the Alpha channel of a vertex color attribute in a Geometry node?

Sounds like you will need to use an attribute created in the shading editor to be used by the Geometry Nodes editor.

+1 good question

If your question has been solved, please be so kind and mark the answer that contributed to the solution as "Accepted answer". This will make it easier for others to see which path leads to the solution, and the question will no longer show as unsolved. Thank you! Here you can find more information: What should I do if someone answers my question?. If you still haven't gotten a solution to your question, please be kind enough to address it.

Blender 3.3+
Things sometimes change for the better, and now also in this case:
Starting with Blender version 3.3, using the alpha channel is possible via the node Separate Color. This is the successor of the node Separate RGB.
This node now splits all channels, and you can additionally choose the mode of color processing:

...and of course this is also possible in the other direction, because the node Combine RGB has also been replaced by the node Combine Color.
Old Answer (Blender below version 3.3)
Unfortunately, the answer is definitely: No, this is currently not possible.
A look at the source code reveals that, although an RGBA color value could in principle be processed due to the variable type, the alpha value is simply not used:
static void sh_node_seprgb_declare(NodeDeclarationBuilder &b)
{
  b.is_function_node();
  b.add_input<decl::Color>(N_("Image")).default_value({0.8f, 0.8f, 0.8f, 1.0f});
  b.add_output<decl::Float>(N_("R"));
  b.add_output<decl::Float>(N_("G"));
  b.add_output<decl::Float>(N_("B"));
}

Source
In contrast, in another part of the code (compositing), which allows the separation of a color into RGBA, the alpha value is very well processed:
static void cmp_node_seprgba_declare(NodeDeclarationBuilder &b)
{
  b.add_input<decl::Color>(N_("Image")).default_value({1.0f, 1.0f, 1.0f, 1.0f});
  b.add_output<decl::Float>(N_("R"));
  b.add_output<decl::Float>(N_("G"));
  b.add_output<decl::Float>(N_("B"));
  b.add_output<decl::Float>(N_("A"));
}

Source
From this we can conclude:
A modification of the source code seems possible and feasible, but currently this function is not implemented yet.


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Not able to render properly
I am trying to learn blender, and I've been doing a fun project based on youtube video last time. I've spend good bit of time on it but I seems to can't Render it properly
This is the project

And here is how it renders, I've been tried to find a solution but I feel like I just can't do it.

You have a few objects hidden in the viewport (eye icon on the far right in the outliner) but they might be still rendered and block your camera. Check the camera icon (render restriction): https://blender.stackexchange.com/a/143192/107598

It looks like something is maybe blocking your camera. Check that nothing is in front of it (don't forget to also check for hidden items)

Omg you are right guys, I am so stupid - this was so easy. Thank you!!!


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How do i track down where image files are referenced from?
When packing external data into a blend file, it comes up with errors saying that several images are missing.  I have tracked down some of the images to materials which came with purchased models (and then deleted them from the material since the files don't exist, and are not that important) but after going through almost every material in the blend file, I still get an error on packing with some images still not being found.
Is there any way to find out where these rogue files are being referenced from.  Looking at similar questions I see some people recommend a materials manager add on which seems to put all images into single directory, but I can't see how that would help me find the materials that are referencing non-existing image files.
Just so annoying that I can't search for the images within the ouliner, and then see their parent material.  Hopefully I'm missing something obvious.

Hi :). Simply go File > External Data > Report missing files. You can see all the missing files listed in the console (Window > Toggle System Console)

Hi Jachym,  Thanks for responding, but it doesn't answer the question.  Doing as you suggest tells me the pathname of some non-existant files, and at that point there is nothing more i can do to fix the problem other than create some dummy images at those locations to get rid of the error.  My question is how do if find where in the blend file these rogue images are referenced so that I can remove/modify those references.

OK... It seems like it is impossible to find where an image is referenced from.   Should be really simple - Blender recognised and reports the error but not where it found it! crazy,

It could be more efficient, but here's a crude script that lists all objects that have materials with image textures, and the image filepath (if it has one) of each image texture.
import bpy

def find_nodes_by_type(material, node_type):
    node_list = []
    if material.use_nodes and material.node_tree:
            for n in material.node_tree.nodes:
                if n.type == node_type:
                    node_list.append(n)
    return node_list

material_set = set()

for object in bpy.context.scene.objects:
    for material in object.material_slots:
        image_nodes = find_nodes_by_type(material.material, "TEX_IMAGE")
        if len(image_nodes):
            material_set.add(material)

for object in bpy.context.scene.objects:
    for material in object.material_slots:
        if material in material_set:
            print(f"Object {object.name}, uses material {material.name}")
            image_nodes = find_nodes_by_type(material.material, "TEX_IMAGE")
            for image_node in image_nodes:
                if image_node.image:
                    print(f"\timage {image_node.image.name} has file '{image_node.image.filepath}'")
                else:
                    print("\tEmpty image texture")

In my project, I don't believe anything was referencing these "missing file" files, but the fact that they existed in the Blender File view caused the "missing file" error every time I saved. I ended up fixing it by doing the following.

Press the Display Mode dropdown in the Outliner:
Choose Blender File
Under Images, right click the offending "missing file" images and hit Delete


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Rigidbody not updating, and not deleting bake
I have 2 objects both with rigid body. One object is active, the other is passive. One active object should be moving after I hit the playback (as its done in the past). However, now the object is not reacting to anything. I've tried deleting the bake within scene properties, however that does nothing as well.
I've tried:
deleting the bake
turning on and off gravity (i've read this resets the rigidbody system).
changing all my objects from convex/mesh.
removing/adding rigidbody systems to the objects
I've been working on this, trying many different little things for 3 days, and am at a lost now :(

maybe you've enabled the Rigid Body "Animated" option? If it's not the case, could you share your file (only keep the object): https://pasteall.org/blend/

Animated option is turned off.
Here is a blend with only the 2 models with the broken rigid bodys. I have also tried using rigid body constraints, but no luck there either as the whole rigid body system seems to be messed up somehow
https://pasteall.org/blend/52cfec70673f44809cd8bf320ffab28f

if you append in a new file it will works but it doesn't answer

it looks like if you Delete All Bakes then Bake All Dynamics it works, I don't know why though

It only worked for me one time, in my scene with the rest of the character. Almost every time bake all dynamics did nothing either. That's ok though. I was going to use rigid bodies to make googly eyes, but its too much of a pain, so I've decided to stick with a traditional eye system, and not use googly eyes!

Have you first Delete All Bakes? Also as I said you can try to append to a new file. Anyway yes perhaps it's not the best solution for eyes

Yes, i've tried deleting the bake many times

Blender 3.6 same issue still exists. After baking rigidbody it gets stuck, I have to delete the rigibody from physics, and assign a new one, this is time consuming when working with cell fracture and over 300 RB. And appears to be the only way to recover the project.


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Mesh is not becoming smooth after rendering
i bought a model from turbosquid which was created in maya with the hypersmooth modifier. In Blender it has very hard edges. So i used a subsurface modifier and a smooth modifier to make it soft again. In the preview render view in blender it looks perfektly smooth but when i render it out it is still edgy. I now increased the iterations of the smooth modifier, it´s getting better but there are still hard edges. Also the Preview Render looks way more realistic in my opinion than the final render.
Use modifer in render is tunred on of course.
https://www.dropbox.com/sh/kc269zv8uptjijz/AACsoeVHyZJjrAptTd1f8Uwxa?dl=0

Use subsurf and shade smooth. Please add images showing the issue.

I already do, but that don't seems to be enough. I render out some samples later.

So i tried some things but now it´s behaving even more strange. Nothing does what it should do...
Here are some Rendereded Images.

Then some Renders with Subsurface and Smooth Modifier. Render Subsurface was on 3 an Smoothing on 2.2 and 3 or 4 Iterations

Then i removed all Modifiers but the result was exactly the same so i deleted them. After that everything was perfect smooth, but now there are some strange Artifacts over the lenes.

After that i tried only Subsurface with render 4

And Only Smooth with again 2.2 and 3 Iterations but that also does nothing now.
Im totaly confused now... nothing works like it used to be.


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Smoothing Edgeloops
I´m modeling a car at the moment. As main reference i use a Blueprint. In the Prozess i offten get dents because the vertevies alonge the edgeloop are not as smoothed as the car would be (of course).

Is there a other way to make the edge loop more a uniform smooth curve to remove those darker parts in the subdiveded Mesh?

At the moment i do everything by hand. Trying to move the vertecies in a way so the darker parts are vanishing.

You could try selecting the affected faces, right-clicking  and selecting Smooth Vertices. You can even adjust the level from the operator panel that pops up in the bottom left afterwards. Be careful though - this may alter the underlying shape of your mesh slightly. Areas that are not selected will not be affected.

see: How do you model panels on a car?

When using as few vertices as that and subdiving, topology is extremely important, and your topo isn't apparent-- the cage display of the subdivision hides it.
In general, a "smooth" operation or modifier can work wonders, although you often want to follow it with a shrinkwrap to a copy of your original mesh to avoid volume loss.
To deal with the explicit title, I would recommend that people install the Loop Tools addon, bundled with Blender, and use "relax" and/or "space" operation to smooth a single edge loop on its own, without respect to other edge loops.


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How can I activate various eyedroppers using script
Now, in order to find an eyedropper I have to click a tiny button, scroll, click another tiny button, click the eyedropper, and THEN I can finally pick a color. I'm aware that with 'E' I can shorten this path a tiny bit, but I would just want a single key-combi for every single eyedropper. ONE CLICK to get the color should be more than enough.
However... I've tried a lot of things now and I can't get it to work.
The first thing was copying the python-tip of an eyedropper (((  bpy.ops.ui.eyedropper_color()   ))) into the console and later into a simple script.
But both come back with {'PASS_THROUGH'}.
I've also tried to put it in a simple Modal Operator, but that gives back nothing.
(I've tried it alone in various places, and in this script here in different places simultaneously. With and without these additions of 'invoke default' etc)
import bpy

class ModalOperator(bpy.types.Operator):
    bl_idname = "object.modal_operator"
    bl_label = "Simple Modal Operator"

def __init__(self):
    print("Start")

def __del__(self):
    print("End")

def execute(self, context):
    bpy.ops.ui.eyedropper_color('EXEC_DEFAULT')

    return {'FINISHED'}

def modal(self, context, event):
    if event.type == 'MOUSEMOVE':  # Apply
        self.value = event.mouse_x
        self.execute(context)
    elif event.type == 'LEFTMOUSE':  # Confirm
        bpy.ops.ui.eyedropper_color('EXEC_DEFAULT')
        return {'FINISHED'}
    elif event.type in {'RIGHTMOUSE', 'ESC'}:  # Cancel
        context.object.location.x = self.init_loc_x
        return {'CANCELLED'}

    return {'RUNNING_MODAL'}

def invoke(self, context, event):
    bpy.ops.ui.eyedropper_color('INVOKE_DEFAULT')
    self.init_loc_x = context.object.location.x
    self.value = event.mouse_x
    self.execute(context)

    context.window_manager.modal_handler_add(self)
    return {'RUNNING_MODAL'}

bpy.utils.register_class(ModalOperator)

# test call
bpy.ops.object.modal_operator('INVOKE_DEFAULT')

There's also 2 different home-made eyedropper-like-things floating around as far as I've seen.
here: https://blenderartists.org/t/pick-the-color-of-a-pixel-in-the-image-editor/575317
and here: (shit I've lost the link, will update if I find it again)
But I can't get them to work. They seem to run without crashes, but they don't do anything for me. Nothing changes. And as I can't fully understand what's happening in them yet, I don't know if this could be part of the solution.
I've also searched a little in the source code, and found this piece of code that's in most of the eyedroppers (at least similar):
/* identifiers */
ot->name = "Eyedropper";
ot->idname = "UI_OT_eyedropper_color";
ot->description = "Sample a color from the Blender window to store in a property";

/* api callbacks */
ot->invoke = eyedropper_invoke;
ot->modal = eyedropper_modal;
ot->cancel = eyedropper_cancel;
ot->exec = eyedropper_exec;
ot->poll = eyedropper_poll;

This seems like a way to interact with the API, but I don't know how and if I could use this exactly.
If someone has anything that might even just lead to a partial solution, I'm all ear!

A year has passed, do find any solution yet?

No, I gave up after a few days of searching

Oh, that hurts.  Thank for reply.   I can printscreen and save as texture using script ( https://blenderartists.org/t/blender-2-9-bgl-readpixels-has-strange-offset-region/1286487    and https://developer.blender.org/T85885  ) .   Perhaps (not test), I can read the correct pixel using script in https://blender.stackexchange.com/questions/70808/how-to-get-screen-color-under-mouse-cursor and https://devtalk.blender.org/t/mouse-position-on-gride-view/6095 .  Just sharing.


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Simple script to resize object
I want to add another menu item to my Custom Panel for scaling the size of an object by +2. I get the following code whenever I do the scaling.
bpy.ops.transform.resize(value=(2, 2, 2), constraint_axis=(False, False, False),
constraint_orientation='GLOBAL', mirror=False, proportional='DISABLED',
proportional_edit_falloff='SMOOTH', proportional_size=1)

How do I pass this code to col.operator() so it works as at the moment I am getting an error.
This is my current code which works fine and allows me to add a plane or cube object.
import bpy

class CustomPanel(bpy.types.Panel):
    """A Custom Panel in the Viewport Toolbar"""
    bl_label = "Custom Panel"
    bl_space_type = 'VIEW_3D'
    bl_region_type = 'TOOLS'

    def draw(self, context):
        layout = self.layout

        row = layout.row()
        row.label(text="Add Objects:")

        split = layout.split()
        col = split.column(align=True)

        col.operator("mesh.primitive_plane_add", text="Plane")
        col.operator("mesh.primitive_cube_add", text="Cube")

def register():
    bpy.utils.register_class(CustomPanel)

def unregister():
    bpy.utils.unregister_class(CustomPanel)

if __name__ == "__main__":
    register()

If all you want to set for the operator is a single property, you can do:
col.operator("transform.resize").value = (2,2,2)

If you want to set multiple properties, use the object that is returned by .operator() and set the properties on it one after another:
props = col.operator("transform.resize")
props.value = (2,2,2)
props.constraint_orientation = 'GLOBAL'

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


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Multiple Animations in the Same Model
I am having a model with two hands that I am trying to navigate. I created one of the moves that I want, then in the action editor I clicked the 'F' button. Created a new action and tried to do changes in the timeline but they affect the previous action as well.
Is there a way to modify the actions independently of one another?
Thanks in advance!

If you mean multiple animation layers (i.e. you animate a walk cycle, then animate different hand movement on top), then no. Blender currently doesn't support that.

The F button is just for making a Fake user to avoid the non-user data being removed after closing.
To make a duplication based on current action data, you need to click the number button next to it.

Thanks but it still messes up my original action. I have the file here if you feel like checking it out:
https://www.dropbox.com/s/hqw66p1qijyr7t8/Go-Today-Backup.blend
Basically I have done the 'today' action and now I would like to create a new one, totally different, but everytime I create it and clear the timeline it make changes to 'today' as well.

Looks fine to me. Can you describe the detailed steps on how you inserted keyframe to the new action?

I think my confusion comes from the fact that it uses 2 separate actions for the different hands. I started all over again and when I moved the second hand it automatically created a new action in the Action Editor. Is that how it is supposed to be?

@user43051 You could use a single action for both hands this would require different keys for each hand, alternatively you could use two actions with each having only keys for one hand (x-flipped).

to make another action you create your first animation make the fake user "little F button" then when your all done with the first action and ready to start the second action, hit the X button to remove that first action from being edited the X will not delete your action you created just unload it from the action editor for editing, then hit the plus again and there you go 2 seperate actions

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


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Resurfacing Mesh After Spin Operation
I'm using Blender to create models for 3D printing.  Right now I'm using the spin tool to revolve a basic 3D shape around a center axis so that it create a set of overlapping identical units.  Think 24 cubes spun around the z-axis to create a ring of overlapping cubes.
This creates 24 overlapping cubes that intersect one another as a single object.  What I need is to remove the intersected areas and create a mesh that is just the surface of this new shape, rather than multiple intersected units.
So far I have tried using the Remesh modifier on the object, but it has not proved helpful.  I'm not sure if this is the correct tool for this purpose or if I am even using it correctly.
What would be the correct way (or at least "a correct way") to do this and achieve the result I am looking for? (Exterior unified mesh with no overlapping internals).

If I understand correctly, you are trying to create a sort of "donut" shape with sharp edges?

To be honest, such workflow should better be avoided, I mean the probability in creating intersection parts that you have to remove then. Or at least you can upload a screenshot to show what you are going to do exactly.

Assuming you got something like that by spinning a cube (Alt-R):

You could simply use a plane for spinning to avoid the issues:

Note: Use Shift-D to remove duplicates and spin operator was invoked  in Edit Mode (Top Ortho View)

You're looking for the Boolean Modifier, which will fuse two meshes when using the "Union" operation.
But if you want to have a perfectly clean mesh, I'd rather advise you to use the Array Modifier to scatter your object around an Empty and edit the object itself to finally achieve your ring.


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Why isn't weight paint affecting his suit correctly?
I made a model of him before and I did everything the same way I did before. The only difference, is that I put clothes on him. I weight painted the arms of his suit the same way as I did his arms, but the suit isn't following the bones like the arms do:c
I'll share a drive link with my blender file in case someone has time and will to look at it
https://drive.google.com/drive/folders/1R6LDpK_TY4knD8Ma8WokY1or82znZknx?usp=sharing

Your normals are inverted, select all in Edit mode and press ShiftN to recalculate the normals, parent the mesh to the armature With Automatic Weights, you'll still need to make some corrections though:

you're a life saver!! Thank u so much! And merry Christmas C:


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why is my curve so blocky?
I followed this tutorial: https://youtu.be/wu_TkcQZqJg?si=ToHyxhPjGI12CqsC
Her curve is somehow much smoother than mine and I have no idea why as I followed the exact steps of her tutorial. I have 4.2.3, she has 3.0.0 (I believe, half of the version number got cut off I the video)

Hello maybe check the resolution of your curve (at the top of the curve panel), if it's not problem please share your file?

It didn't solve it:c thanks for the help!!
https://drive.google.com/file/d/1DO9Ax7fyiviTzeHNKr3LeLujhsEz_-po/view?usp=share_link

what kind of curve have you created? You need to create a nurbs, a path or a bezier (Shift A > Curve > ...), I guess this is the nature of your curve that causes the problem here

that didn't work for me unfortunately. I made a path, and a path circle, and then selected the path so I can eyedrop or select the circle as the bevel object but blender didn't find it nor recognized it with the eyedropper

oh ok i get it, under Active Spline, increase the Order U value (I'm not familiar with Path curves)

Under Active Spline, increase the Order U value:


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Bones point towards ground
Looking for a way/constraint to point bone towards ground, always. I am trying to build a robot leg with a toe, and when the leg moves up, the toe points down, unfortunately I am not able to find a way to do it other way than manually.
Thanks :)

You'll have to utilize more bones and constraints for this
I'm not sure if this is exactly what you are looking for but maybe it can be a starting point.
The toe bones have a "Locked To" constraint which are tracking the "track_to" bone, I set up a foot bone which is what you will animate and the "track_to" bone will follow the foot bone along the ground which has "Copy Location" constraint on it. Download the Blend if you want to deconstruct the setup.

Bonus Gif

Wonderfu, that is exactly what I needed, thank you :)


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Blender game Engine collision sensor, property value
my problem is that i have 3 platforms that react to a specific object.
If the object hits the platform i want to change the property value to 1, so that my game knows theres the object on the platform.
Sadly it seems like the property value doesnt count up.
my blender version is 2.79a
Greetings
Jonathan

I fixed the problem, i had to activate the TRUE level triggering, now it works


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Subdivision surface viewport problem - edges buried in mesh
I'm doing retopology with subdivision surface and shrinkwrap modifiers. In yesterday's project, the viewport behaved like this:

Today it looks like this:

The problem is that the "control points" (actually just the pre-modifier mesh) gets buried inside the mesh and I can't see what I'm doing. In the other file the edges were curved with the subdivisions, making sure they were always visible.
The subdivision surface modifier settings are identical for the two files, so the issue must be elsewhere.
Thank you!

Found it!

The trick is the little triangle icon (Adjust edit cage to modifier result) on the shrinkwrap modifier
Again, not on the subdivision surface modifier but on the shrinkwrap.

That button will get enabled on both modifiers actually since enabling it to the second modifier in stack makes first adjust its result to the cage as well. However that's true that if you have such jagged edges of the lowpoly look up the modifiers, since edge made of 2 vertices dy definition can't be anything other than straight


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Baked normal map partially inside out (Blender/Unity)
I'm baking a normal map using a high-poly mesh and a low-poly mesh. Things seem to work out, except some UV-islands are... inside out?
In unity it looks like this:

The left image has normal map strength set to 2.0 (exaggerated for clarity) while the right image has normal map strength -2.0
As you can see, in the left image the left wing is inside-out while the right wing is correct. In the right image it's vice versa.

I have tried normal recalculating, flipping etc.
Thank you!

So apparently a thing that can happen is that the unwrap algorithm puts down some islands mirrored. A way to see this is to view the model with the grid texture and look for flipped letters/numbers.
Hope that helps someone out there!


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Having trouble symmetrizing
I'm trying to symmetrize an object (in this case an airplane as I'm following a beginner tutorial) and am having some difficulty.
As instructed, I'm in edit mode, clicked the "A" key to select all, then went to "Mesh" > "Symmetrize"
When selected it looks like this, just like in the tutorial

However, when I hit "Symmetrize" this happens, instead of adding another wing on the other side as intended.

I notice it logged an error regarding the symmetrizing on the bottom

From a bit of Googling I tried the "Snap To Symmetry" option right under "Symmetrize" in the "Mesh" menu.

I changed the direction, threshold and factor a few times but nothing seemed to work. I'm assuming -X to +X is what I want since that's the red line.
Thanks for the help!

Change it to (+X to -X) instead of (-X to +X)

That was actually it! I had tried that (as mentioned in the question) but for some reason the first few times it didn't do anything. Maybe the direction variable needed to be set somehow before clicking "symmetrize" again. I played with it for a bit and got it to work.


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Render Picture id to dark
every time whem I'm rendering my picture it is very dark.

But my Layout looks like this:

Maybe the Problem is that I rotatet the light in the viewport shading?
Without rotation it looks more like the picture that I rendered
If I rotate everything about 180 degree it looks the way I want but that wwould mess up my animation :(
What can I do to fix this.

Hello and welcome. it looks like your scene does not have any lights. The included HDRIs are for the render preview viewport. if you wanna use those see this

in the Viewport Shading panel you need to enable the Scene Lights and Scene World options


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Rotation in Pose mode is wrong/off, rotation x axe
I'm trying to recreate this Pose.

This is what I have so far, but every time when Im trying to use the x axes it rotates in the wrong way.

A few more examples pictures

Its the same for the z axes.
It looks like that every rotation I make is along the y axe. I have no clue why.

hello, maybe share your file (only the armature if your prefer not to share the character, share the link it will give you): https://pasteall.org/blend/

I found the problem. I locked the other axes.


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How do I remove this line from the render in the compositor?
I am using the compositor to draw an outline around objects, but I want to be able to remove a specific part from the outline.

What I want is to be able to remove the outline that appears at the intersection. I can isolate it using cryptomattes but from there I have been unable to remove it from the render. I have mainly tried the mix/math node and trying to convert the image into an alpha mask but it never got the what I needed exactly.

Use the separated line as a factor to "mix color" between the original image and the new image. Maybe use a color ramp with constants to clearly separate values before the mix.


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How do I separate a mesh from this object?

How can I separate the leg from this model? I have this mesh I have aligned so that I could cut with it.
I did this in Rhino 3D no problem but cannot figure out how to do it in Blender as I am new to the software.
Also if there is any other way to do it easier help would be appreciated...

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

Duplicate your character to keep a copy somewhere. Give your character a Boolean modifier and use the mesh as Object of the Boolean, if your character is manifold it should work:

1 - Select the edge that you want to separate:

2 - Right click, mark seam
3 - Select any vertex/edge/face on the leg
4 - ctrl+L, select the seam option (it will select the entire leg if you did the seam right)

5 - Press P to separate and select the "seam" option


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Blender 3.0 I am having a problem while adding empty
My empty always appears as a small dot and does not work correctly during any project but it occurs completely fine in an empty 3d viewport but not during projects.

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

Expand the operator properties window at the bottom left and increase the Radius parameter.

@DuarteFarrajotaRamos He appears to have just deleted his previous question and the operator properties dropdown is bottom-left, not bottom-right! :^)

My problem is mostly solved thanks for your guidance, the only thing I am facing now is it still doesn't work when I import a city model from sketch fab. I believe this is occurring due to the import . Is their anyway to solve this also?


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How to create procedural ceiling tile Gradient texture?
I'm trying to create a procedural drop ceiling texture, and I have been able to create a simple one, even one with stains/water damage. However, I would like to try add depth to the texture, specifically by overlaying a gradient texture over individual tiles, and having it be randomized in rotation (increments of 90 degrees) and location. Additionally, I'm not using geometry nodes, as the texture is a custom PBR. Does anyone have any suggestions, or at least any advice?

Here's the texture without stains.

Here it is with stains.

There might be many different ways of doing this, but one that matches your tiling would sort of require us to know how you're making the tiles.

There is no geometry to the ceiling tiles, as it's purely a flat texture repeated.

That is not enough... is each tile "one image"? Is it procedural? Is it a file?

The texture is a square image, and it's 5 x 3 tiles. I've just used an Object texture coordinate and the correct face attributes option to repeat it. I'm wondering how to overlay a grid that has the same size tiles, but has differently oriented gradients in each.

You can probably adjust the input values here to match your texture.

Where:

Offset_X and Offset_Y: values that you adjust to slide the gradient tiles
Tiles_X and Tiles_Y: values that you adjust to control de number of gradient tiles in each direction (in UV for a plane, this number matches exactly, in "Object", the result seem to be doubled, you will need to find what is optimal for your case)

Explanation:

Using "snap" in the vector creates constant regions without variation in coordinates. Each constant reagion is a tile
When you feed snapped vectors to the noise texture, it samples a constant noise for each tile
In parallel, we scale and repeat the vectors for creting gradients. The floored module tells how far from a step value the coordinate is.
An additional mapping with (location = 0.25 and scale = 0.5) is used so the gradient doesn't reach its limits (0 and 1). It gets constant on the limits and we don't want that.
We then use the constant noise values to rotate the tiled vector and input to the gradient texture


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Geometry Nodes grow
Is it possible to make this thing grow along the curve?
like a vine

Just trim the curve before resampling.
Use the current frame as factor for the length.

In the picture:

"Total_Frames" is a "Value" node, I set the duration of the animation there
The value in the "Divide" node is #frame (a driver that gets the current frame number)

Basically: trim_factor = current_frame / total_frames
(Alternatively, instead of using a frame driver, you can use a "simulation zone" node)

It worked!! thank you so much!! :D


text:
Assigning multiple values received via ZMQ to nodes?
I'm trying to take data streamed over LSL into Blender to dynamically update my animation. I've succeeded in my LSL processing, and streaming using ZMQ. When I connect to the socket using the GUI button in Blender, it's clearly getting connected:

but it's not updating dynamically with new data, like this tutorial shows.
And finally, I think I'm having issues decoding the dictionary to alter the parameters of interest. Over a few days I've cooked this script up with ClaudeAI and it's clearly trying to work, all the keyframes appear and it slightly buffers when I hit "run" but I don't think the numbers in the dictionary I'm sending over are getting picked out right.
import bpy
import zmq
import json
import threading

# Define the object and nodes
aurora = bpy.data.objects.get('Aurora')
material = aurora.active_material
geo = bpy.data.node_groups['Geometry Nodes']
hueNode = material.node_tree.nodes[8]
brightNode = material.node_tree.nodes[3]
wiggleNode = geo.nodes[19]

# Normalize input number across the purpley color range
def colourRange(valA, lA, hA):
    valA = max(min(valA, hA), lA)
    facA = (valA - lA) / (hA - lA)
    return 0.68 + facA * (0.9 - 0.68)

# Normalize Emission node brightness
def brightRange(valB, lB, hB):
    valB = max(min(valB, hB), lB)
    facB = (valB - lB) / (hB - lB)
    return 11 + facB * (17 - 11)

# Make it wiggle a bizzle
def wiggleRange(valC, lC, hC):
    valC = max(min(valC, hC), lC)
    facC = (valC - lC) / (hC - lC)
    return 0.3 + facC * (1.2 - 0.3)

class DataManager:
    def __init__(self):
        self.data = None
        self.lock = threading.Lock()

    def update_data(self, new_data):
        with self.lock:
            self.data = new_data

    def get_data(self):
        with self.lock:
            return self.data

data_manager = DataManager()

def receive_data():
    context = zmq.Context()
    socket = context.socket(zmq.SUB)
    socket.connect("tcp://127.0.0.1:12346")  # Connect to the publisher
    socket.setsockopt_string(zmq.SUBSCRIBE, 'eeg_audio')  # Subscribe to 'eeg_audio' topic

    while True:
        try:
            topic, message = socket.recv_multipart()
            data = json.loads(message.decode('utf-8'))
            data_manager.update_data(data)
            print(f"Received data: {data}")
        except zmq.ZMQError as e:
            print(f"ZMQ Error: {e}")
        except json.JSONDecodeError as e:
            print(f"JSON Decode Error: {e}")

def run_server_in_thread():
    server_thread = threading.Thread(target=receive_data)
    server_thread.daemon = True
    server_thread.start()
    print("ZMQ subscriber thread started")

def update_animation(frame):
    data = data_manager.get_data()

    alpha = data.get('alpha', 0)
    theta = data.get('theta', 0)
    avg_envelope_data = data.get('audio', 0)

    # Set the frame in Blender
    bpy.context.scene.frame_set(frame)

    # Alpha to Hue
    modHue = colourRange(alpha, 1000, 2000)
    hueNode.inputs[0].default_value = modHue
    hueNode.inputs[0].keyframe_insert(data_path='default_value', frame=frame)

    # Audio to Brightness
    modBright = brightRange(avg_envelope_data, 0, 100)
    brightNode.inputs[1].default_value = modBright
    brightNode.inputs[1].keyframe_insert(data_path='default_value', frame=frame)

    # Theta to wiggle
    modWiggle = wiggleRange(theta, 3000, 10000)
    wiggleNode.inputs[1].default_value = modWiggle
    wiggleNode.inputs[1].keyframe_insert(data_path='default_value', frame=frame)

    print(f"Animation updated for frame {frame}")

def frame_change_handler(scene):
    # Update animation for the current frame
    current_frame = scene.frame_current
    update_animation(current_frame)

    # Update Blender's UI
    bpy.ops.wm.redraw_timer(type='DRAW_WIN_SWAP', iterations=1)

def main():
    # Start the ZMQ subscriber in a thread to keep Blender responsive
    run_server_in_thread()

    # Clear existing frame change handlers to avoid duplicates
    bpy.app.handlers.frame_change_pre.clear()

    # Register the frame change handler
    bpy.app.handlers.frame_change_pre.append(frame_change_handler)

    print("Blender script initialized. Ready to receive data and update animation.")

if __name__ == "__main__":
    main()

If anyone knows anything to help fix this, in order to decode the dictionary properly and to then update the relevant nodes, please tell me!


text:
How do I assign to a vertex group with geometry nodes?
I'm working in Blender 2.93 Alpha (more details if needed), and I'm looking for a way to apply a solidify modifier to only a specific vertex group. However, I can't figure out how to assign pieces of my geometry node group to the vertex group.

I may have misunderstood the question, but as I understand it you could use an attribute mix node with the factor being the vertex group, and the inputs being the different "branches" of the node network you want applying. In this example I mix two sets of points, one from a scaled up sphere and one from the original vertex position. For the solidify modifier you can just use the vertex group input, with a group. Sorry if I misunderstood the question.

Actually, I was asking more of something like this:
I have an object which is created entirely with primitives and transformations using geometry nodes. I need a way to solidify one of these objects, without doing it to the rest of the geometry. How do I assign vertexes to a vertex group using geometry nodes?


text:
Blender suddenly wont open/reopen any of my blender projects
Yesterday I made a few projects in Blender 2.8. All day I was able to save, close, and open them. Today, when I try to open I get an error message saying blender previously crashed, do i want to reopen? when i click "reopen" it's just cycles back to the same error message.

did you try to reinstall blender or download a newer version?

I've reinstalled. I'm using 2.9. I've installed on my husband's PC and tried there. Still froze when I try to use boolean tool. I ditched that file all together, started a new one. Now that file freezes when I use boolean. (I am applying the boolean effect every time, so no stacking here). No one can tell me why this is happening. The only thing I can think of is that my preferences are set up weird or something.


text:
Change spacing between loop cuts
What is the best way to achieve loop cuts like this please:

Create loop cut with CtrlR, keep them selected, bevel with CtrlB.

That's clever :)

Seems rather like a basic, no?   ;)

Just as I think I'm getting better at this, something so simple trips me up and makes me question my whole life! Thanks @moonboots

@user122169 Don't forget to mark the answer as accepted if it helped :)


text:
Black patches appearing on glass materal in cycles in viewport preview
I have a glass material applied to an object I am rendering in Cycles, but whenever I render it the material generates these black squares around it. the Object is light by an HDRI, however even without the HDRI it still has this issue. I changed the values in the "max bounces" section of the Render Properties tab, but to no effect. I'm stumped, what is causing this? Is there an obvious setting I'm missing?
Any Help would be much appreciated!

Probably a bug.

Can you share the blend file? Make sure to include all the texture files.


text:
Set origin to Matrix_world bottom center of Lego bricks's bound box
I have a lego 3D objects, in blender 2.92.0. And I would to set the origin to Matrix_world bottom center of Lego bricks's bound box, then set all bricks to z = 0.
I am a newbie in blender, so I'm trying run the code from batFINGER .
import bpy
from mathutils import Matrix, Vector

def origin_to_bottom(ob, matrix=Matrix()):
    me = ob.data
    mw = ob.matrix_world
    local_verts = [matrix @ Vector(v[:]) for v in ob.bound_box]
    o = sum(local_verts, Vector()) / 8
    o.z = min(v.z for v in local_verts)
    o = matrix.inverted() @ o
    me.transform(Matrix.Translation(-o))

    mw.translation = mw @ o

for o in bpy.context.scene.objects:
    if o.type == 'MESH':
        origin_to_bottom(o)
        #origin_to_bottom(o, matrix=o.matrix_world) # global

and this code:
from mathutils import Matrix, Vector
import numpy as np

def origin_to_bottom(ob, matrix=Matrix(), use_verts=False):
    me = ob.data
    mw = ob.matrix_world
    if use_verts:
        data = (v.co for v in me.vertices)
    else:
        data = (Vector(v) for v in ob.bound_box)

    coords = np.array([matrix @ v for v in data])
    z = coords.T[2]
    mins = np.take(coords, np.where(z == z.min())[0], axis=0)

    o = Vector(np.mean(mins, axis=0))
    o = matrix.inverted() @ o
    me.transform(Matrix.Translation(-o))

    mw.translation = mw @ o

It's looking like something is wrong, but I can't find out the reason. So, what can I do now?

guys. I get the answer about the question. Thanks for the help from Martynas Žiemys
this is the code:
def origin_to_bottom(ob):
if ob.mode != 'OBJECT':
    bpy.ops.object.mode_set(mode='OBJECT', toggle=True)

d = ob.data
m = ob.matrix_world

bounds_center = (sum((m @ Vector(b) for b in ob.bound_box), Vector()))/8
difference = m.translation - bounds_center
local_difference = difference @ m
for v in d.vertices:
    v.co += local_difference
    m.translation -= difference

difference = Vector((0,0,0))
bound = min((m @ v.co).z for v in d.vertices)
difference.z = m.translation.z - bound

local_difference = difference @ m
for v in d.vertices:
    v.co += local_difference
    m.translation -= difference


text:
Creating pose library thumbnails in Blender 4.2
I'm an animation newbie trying to use the pose library. I can create and reuse poses, but each pose has a generic image that looks like an exclamation mark.Regenerating the image doesn't make any difference. Any suggestions?

I solved it (I think) by making the character appear in the appropriate size in camera view. No color, but at least the pose is there.


text:
Turntable rotation after changing keymap

Hi. I'm creating my own custom keymap which is far more intuitive for me. So when I press E (which is my rotation now) and then press R (which is my scaling), a red/green cursor appears and I can rotate this object on all axes. Blender still recognize combination E-R as double clickin rotation key. I looked for it in the keymap but I can't find what it is exactly.

It's called "Trackball" (as shown in the top left corner of the screen). The search for the keymap doesn't seem to be able to find it. But you can find it if you search for the 'R' key binding for rotation ('E' in your case, I guess). It's in 3D View > Object Mode > 3D View Tool: Rotate > [X] Rotate > Transform Modal Mode > [X] Trackball -> (R)

Yeah it's called "Trackball" you are right. "ut you can find it if you search for the 'R' key binding for rotation ('E' in your case, I guess). It's in 3D View > Object Mode > 3D View Tool: Rotate > [X] Rotate > Transform Modal Mode > [X] Trackball -> (R) –
" sorry but I can't find it on my screen. Can you post a screenshot where it is exactly?

It's called "Trackball" (as shown in the top left corner of the screen). The search for the keymap doesn't seem to be able to find it. But you can find it if you search for the 'R' key binding for rotation ('E' in your case, I guess).
It's in the User Preferences > Key Map, there expand 3D View
> Object Mode > 3D View Tool: Rotate > ☑ Rotate > Transform Modal Mode > ☑ Trackball → R

expand ☑ Rotate and scroll down, there you find Transform Modal Mode ...

Unfortunatelly your solution doesn't work.

what does not work? Does E-R still activate the trackball mode?

Yes. E - R still activate the trackball rotation mode.


text:
View length when using Draw Cube (add cube) tool
I do hammer-style level design in Blender, and I want to know the dimensions of cubes/blocks i create using the "add cube" tool that allows you to draw the cube.
It's actually quite nice how you can snap it to grid and orient it to the surface, or any axis. The only issue is that I want to be able to tell the width/length/height of a cube WHILE i'm creating it. The grid floor is not a solution, because any complex environment will always be above or below the grid, and the grid will be hidden by other geometry anyway.
I would like to be able to know what part of blender's code to edit, or how to write an addon so that I could know the length of the sides of the cube as I'm creating it.

FWIW. I don't know anything about hammer-style level design. If you have Developer Extras checked in the Display section at the top of Edit->Preferences->Interface and you right click on the Add Cube tool, you get options to View Source, Copy Python Command and for the online Blender and Python manuals sections regarding it. But, they cover creating the cube only. It doesn't look to me like there is a way to display dimensions in the way that you want to.


text:
How to get column values from SpreadsheetColumn from SpaceSpreadsheet.columns?
I can get column name from SpreadsheetColumn but how to get column values from SpreadsheetColumn? I have enclosed python code and screen shot. Request any one help.
Thanks
Screenshot link
https://drive.google.com/file/d/1i4KuEDs4Z--V0bva76idwkREAcfTe7Ru
Code:
import bpy

def find_spreadsheet_space():
    # Find 3D_View window and its scren space
    area = None
    for a in bpy.data.window_managers[0].windows[0].screen.areas:
        if a.type == "SPREADSHEET":
            area = a
            break
    return area.spaces[0] if area else bpy.context.space_data

s_sheet = find_spreadsheet_space()

print(s_sheet) # SpaceSpreadsheet

collist = s_sheet.columns
print(collist)   # column collection

print( s_sheet.columns.items() ) # tupple

for col in s_sheet.columns.items():
    print(col[1])                      # Getting SpreadsheetColumn
    print(col[1].id)                   # Getting SpreadsheetColumnID
    print(col[1].id.name)              # etting SpreadsheetColumnID name

#Result:

#<bpy_collection[1], SpaceSpreadsheet.columns>
#[(0, bpy.data.screens['Scripting']...SpreadsheetColumn)]
#<bpy_struct, SpreadsheetColumn at 0x00000137C70A1C80>
#<bpy_struct, SpreadsheetColumnID at 0x00000137C755D920>
#position

# How I can get column name from SpreadsheetColumn
# but how to get column values from SpreadsheetColumn

Hello and welcome. Instead of having users go through links and external sites please use the builtin tools to embed images in your post. See How to upload an image to a post? or GIF


text:
render output is weird
my render output has a weird looking shape and color which is different from what I see in layout. the version I am using is 2.92. does anyone know what's wrong with it and how to fix it?
this is what i got after hitting F12 button:

this is what I see in layout:

Does this answer your question? Why are there non-visible objects in my final render?

You have a hidden object, "Donut2".
This only hides it in viewport, not in render. You can go into the object properties and disable render, or delete the object.


text:
material not applying
I have my material nodes set up, however, the viewport is not showing any changes.
my nodes were set up like this:

and the viewport is displaying:

i wonder how to fix it.

please provide blend file

This looks CORRECT to me. The transparent node only lets red light through, so cyan light is reflected back at the camera. I might try changing this whole setup to either a Transluscent BSDF, or a Principled BSDF and turning on subsurface scattering.

I’m sorry, I’m looking at this with night shade thingy on. Regardless, your node setup only has one tiny color property in the transparent node, limited by fresnel, with white on white with the other two nodes.

I guess change the render engine to cycle and select rendered by holding Z key.

Looking at your node setup, your Transparent node is quite a dark red which doesn't bring much color to it, and the Density of the Volume Absorption is set to 204.8 (!). This hardly lets any light through... values of 0.1 to 1 or may even 2 might work, but over 200? And the Material Preview doesn't work well with transparencies and volumes. Maybe switch to Rendered View.


text:
Will Nvidia Geforce GT 1030 work?
I have a GT 1030 so I am wondering will it work with Blender CUDA? If yes, what should I do to make it work?

I have not been able to render with this card... I get an out of memory error

The Nvidia GeForce GT 1030 supports CUDA 6.1 rendering, therefore it is compatible with the most recent version of Blender Cycles rendering. (Currently 2.92). To make it work, simply select and enable it as a Cycles CUDA rendering device in the Blender Preferences, then select GPU rendering in the Cycles rendering properties panel.


text:
No fluid generated when baking data + baking mesh (2.90.1)
trying to create an effect of blood dripping that will be late composited into a video.
I've tried changing the scale, resolution, particle min/max, but no matter what i do, baking the data+mesh on the domain does ostensibly nothing.
here is my .blend. Any help is appreciated
https://drive.google.com/file/d/1e79pF90GDRhpCRtXR6Dy1S4-1wWk0pV7/view?usp=sharing
there is another object below the inflow object thats meant to throw the blood outward a bit, although i dont think that it is a factor
screenshot of workspace:

When there's no emission, look first at the emitter (Circle, Inflow). Your "Circle" object, although converted to a mesh, may have insuffient surface areas to emit anything.  I checked the Is-Planar in the screen-cap below, and all started to work, even after reducing the Domain's Resolution from 200 to 100 (faster simulation, less accuracy).

I had a similar "dripping blood" for an animation.  It took some patience to get the effector animated to occasionally drip and not occasionally pour.   You might want a few, smaller circles with animated "Use Flow".  Or instead of a circle with "Is planar" (inaccurate), consider using a cylindar, and adjust the Z-dimenison (smaller == less flow).  Or continue to use your circle but scale X&Y.


text:
Problem with extrude along the local axis hotkeys
tell me, I'm going through the lesson, the teacher at 2.82 turns out to extrude two faces symmetrically along the local Z axis through E-S-Z-Z, and for some reason, in my case, in 2.92, E-S-Z-Z extrudes along the normals, why, and how to fix it?

Try S-Z-Z without E, this should work.

But what I need is a symmetrical extrude along the local axes. I can achieve a similar result from the tutorial through E-esc-G-S-Z-Z, but it's longer and more confusing.

If you press a key for an axis like Z multiple times after activating a transformation like Scale (S), it will cycle through a few Transformation Orientations (Local, Normal, Global, ...).
You may have set a different value in the "Transformation Orientations" selection box than in the tutorial. Check the value of this box.
The selection box is located in the top center of the header of the viewport (or at the bottom of the viewport if the header is there). See screenshot here in Blender's documentation.


text:
what's wrong with my armature
when I parent my armature to my mesh with automatic weights, the mesh deforms and I can't figure out the reason

Hello, if Crantisz' answer doesn't answer, please share your file: https://pasteall.org/blend/

Hi Please use a title that reflects the content of the question. It should be descriptive but succinct, unique and identifying, summarizing the issue so that users can at a glance understand what your post is about. Use the [edit] link below your post and avoid anything not strictly essential to the post. Remember, your title is the first thing potential visitors will see, and makes your question findable for future users. See "What is the problem with posting an image or link and asking “How do I do this?""

Try to select bones in pose mode and press alt +S to clear scaling. If you have scaled bones in pose mode, it will affect on the mesh.

You must mean Alt S?

Oh, yes, of course

the scale and rotation are fine. I tried playing with the pole angle too but that wasn't it either. if I go into edit mode, the mesh is fine however if I enter object mode or pose mode, the mesh becomes deformed. also, i noticed if i scale the entire armature down and then parent the mesh, the mesh scales down with the armature. im not sure if that supposed to happen


text:
2D grease pencil layer disappears when parenting to armature bone
I am following a tutorial on how to rig and animate a 2D character. I am using Blender 3.2.0. I have the character as an object consisting of several grease pencil layers. As per the tutorial I setup the armature and built all the bones. As per the tutorial I now have to parent the object's grease pencil layers to the bones. I start with the fringe of the hair grease pencil layer for which there is a fringe bone and do the following (as per the tutorial): In Object Mode select the object (the character) and in the Properties panel go to the grease pencil tab group and in the Layers select the fringe layer, then in the Relations settings select the Armature as the Parent and the fringe bone. I do this and then my fringe grease pencil layer disappears. I tested with the hair grease pencil layer and bone as well, the same thing happens. I am sure it is a silly setting or something I unknowingly did, as newbies always do, if someone can give me tips to resolve this I will greatly appreciate it.

After hiding all other layers I was able to establish that the grease pencil layer is being transformed to somewhere in the middle of the character, hence I did not see it it is hidden by the other layers, so I know now it is being transformed by the parenting, but how to fix it, for grease pencil layer parenting I cannot see any way to preserve the layer's offset?

Also need to mention I did zero out (freeze) all transforms of everything.

I think I found the problem, the character is originally from an svg file imported with several curves, these are then converted to grease pencil objects and joined togehter to form the character, there is a step I missed, after converting the curves to grease pencil objects I had to zero (freeze) transforms of the grease pencil objects before joining them all in one. After joining I moved the character to the center (was not centered, well it is not semetrical character) and then had to zero out again.


text:
computer reboots during cycles rendering on Blender 3.2 and 3.3
I've recently been trying Blender and couldn't get it to render cycles without rebooting after just a few second. I tried to log information into a file (blender &> blender.logs ) but it seems that the reboot occurs without warnings to the program.
Blender 3.1 is rendering just fine, no matter the complexity of the scene so far.
Blender 3.3 alpha and 3.2 stable do reboot on the most basic cycles rendering (the cube). This occurs on CPU and GPU rendering within 5 seconds, constantly, no exceptions.
I have an i9, gigabyte motherboard and an Nvidia RTX 3060 (510, proprietary drivers). I run Ubuntu 22.04 but this also happened on ubuntu 20.04 LTS. Hardware wise, I've used my Nvidia card for neural network training without any issues and I've stress-tested it on a 3D benchmark without any trouble (so I could rule out power/PSU concerns).
I understand this is very little information for debugging but maybe someone knows a way for me to capture more information that would provide the community with more insights?
Thanks

Just a question for debugging purposes - are you running any overclocks at all (aside from basic memory/xmp)?

No overclocking on the CPU nor the graphic card. After 3 days of trying and reinstalling Ubuntu, this morning, 3.2 started rendering just fine... I have no clue what is going on.  Could installing 3.1 remove the bug from 3.2 somehow?


text:
How to split a plane into n-gon mesh as defined by the voronoi color texture?
The Voronoi color texture splits a plane into convex n-gons. How to get a mesh with the same topology with clean edges defining the color borders?

https://en.wikipedia.org/wiki/Fortune's_algorithm

You might look into cell fracture, as it does something similar. This pattern is created by distorting a grid, in this case 3-D, and slicing it with the 2-D mesh surface.

Incrementing on my idea from here:
How to achieve Geospatial Voronoi pattern?
For each non-top point of a cone I move it to the top of the cone and raycast down the cone (along the opposite vector to the one used to move it to the top of the cone) to hit another cone, and move there to find an intersection:

Clearly this is resolution based and imperfect, just a lazy approach:

.blend 4.2

I looked at the content you linked in the comments and racked my brains. I think the idea of putting this on the Z axis is brilliant! Even though it doesn't give the same result as the Voronoi Texture Node and still creates a lot of geometry in between, I love this approach (and of course the result)! Cool! A typical Markus von Broady answer!

@quellenform it absolutely does produce the same result as the Voronoi Texture node, you just need to synchronize the starting points: https://i.imgur.com/Rkz6qnL.png then the result lines up: https://i.imgur.com/Y1Ptppi.png

Ah, great, I obviously made a little mistake when testing. Wonderful!


text:
Object casting duplicated shadows on different objects
I'm inserting few objects in blender after doing motion tracking on a video.
There's a plane that represents the floor (set as shadow catcher) and then, as you can see in the image there's a sort of disc on which I put a sitting character. I don't understand why, but the character is casting a full shadow both on the disc and on the floor below it.

I would expect that the shadow on the floor would only be the character's parts exceeding the disc, but they are both "full" shadows. What am I missing here? Something about view layers? Thanks in advance.

can you please share a simple sample file with this problem? https://blend-exchange.com/

It looks like you use this set condition ...

Upper Plane is with Visibility > Shadow Off ... Lower Plane with Ray Visibility > Shadow Catcher On

To fill your expectations (if I reconstruct your scene right) - your shadow catcher object should be at the same height as the disc with Ray Visibility On.


text:
Check whether shortcut key exists/don't allow shortcut key to mutliple actions
Is there an easy way to check whether a shortcut key exists already? I wanted to assign ctrl+s as "mark seam" but immediately realized that that was already the save shortcut. I'd like to be able to check whether there would be a double assignment, and if possible, not allow them.

There is an addon already built into Blender (but not on by default) called "Is Key Free". It allows you to enter a key and check it for its uses. After turning on the addon, open the Text Editor, and look in the sidebar to the right of it for the Dev tab. Under that is where you will find the Is Key Free addon, once it has been activated.

Header > Edit > Preferences > Keymap ....

... search as shown, with a string representation of your shortcut.
You will be shown a list of context-dependent uses of the key combination.


text:
How do I make a sphere with 5 flat sides?
What it says in the title, I'm trying to make a sphere with 5 flat sides so I can place a cone on top each one in a star esque pattern but I have no idea how to do so. Ideally they'd want to be equal in radius. Thanks for reading.

I'm not sure it's possible: https://en.wikipedia.org/wiki/Platonic_solid Only these can have truly equal sides.

It sounds like you don't have a clear picture of what you want, or you haven't described it well, because 1) a sphere doesn't have sides, 2) a 5-sided solid can't have equal faces 3) a 5-sided volume would have 5 vertices, which seems REALLY straightforward to model. So I recommend updating your question with something specific that you've tried, but hasn't worked, or a particular part of the process that you're finding difficult (e.g. "I have a 5-sided solid, but how can I make all the faces equal?", or "How do I make sure that each of my vertices is the same distance from the center?")

Are you looking for something like this?

gandalf3 has the right idea. What I mean is a sphere with 5 flattened planes going radially in a circle, similar to that image.

Ideally my result would be similar to this except all as one mesh, instead of a few cones stuck onto a sphere.

To simplify the question to the problem I'm having. How do I make a Circular hole on the surface of a sphere?

hmmm, now you're asking a slightly different question. Do you need to update/clarify your original question?

This doesn't need to be closed at this point, but Broand really needs to figure out what exactly he's trying to ask. Broand, please sketch it on paper and upload a scan or something. Just get your question straight so we can answer it in a constructive way.

Another method:

Add a sphere (both types will work).
Add a cylinder with five verts:

Add a boolean modifier to the sphere and select the cylinder as the object:

Scaling the cylinder on the X and Y (SShiftZ) axes will change the radii of the flatten areas.
Apply the modifier and select the flat faces (the fastest was is probably by selecting one and pressing ShiftG> Area):

Press AltP and the select the center vertices:

Scale the vertices out (S). Then optionally set shading to smooth and add an edge split modifier:

The simplest method would be to use a bolean modifier:

Add Sphere
Add Cone
Go to Modifiers
Select Generate->Boolean
Operation -> Union
Object -> Cone
Apply

To distribute 5 cones around a point:

Create Cone
Move cone above rotation point (0,0,0)
Go into edit mode
Add -> Spin

Set Center of rotation (0,0,0)
Angle -> 360
Axis -> X -> non-zero


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What are alternative methods to Fluid for making a glass appear to be full of liquid?

What are alternative methods to Fluid for making a glass appear to be full of liquid?

I just require a quick simple method. I was going to use particles but wondered if anyone had other methods or ideas.
Doesn't need to be too realistic as it's only for a small static image project.

does it need to be animated?

No not animated at all.

One way is by simply creating a face for the surface of the liquid, and then use separate materials on each interface as in this post.

How about if the glass container were an odd shape?

@FoxyFish It's still the same idea, you just have to figure out how to make a face from the glass (extrude and merge works well). For most shapes it shouldn't be hard, but I can't give any more detail without knowing what the shape in question is.

You can select an edge loop (add one if needed) near the water level. Shift-D to duplicate the verts and E to extrude scaling inwards to fill in the surface. This will give you a water surface to match any shape.

@sambler Unless you have a really strange shape like a jug with a hollow handle or something. Another thing to remember is to add a little surface tension to the liquid surface too.


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Is it possible to select a face in the UV editor and find it in the 3D View?
I have a mesh which i have Smart UV projected , and i have many loose UV faces . I would like to know if i am able to select a face in the UV/Image editor , And make it select the face on the 3D mesh. Is this possible?
I cannot select every face on my 3D mesh to find the correct face in the UV , That is very time consuming and confusing. Thank you.

In the header of the UV editor window there's a button named Keep UV and edit mode mesh selection in sync, an icon with an arrow pointing to a cube mesh.
That solved your problem.
Consider that also in the UV window you can choose if to work with vertices, edges or faces.
Note that if this button is selected, you can't edit the UV islands.
UV Sync Selection button:


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Remove a few particles?
*I dont know how to explain the title feel free to change
I have downloaded a mesh that uses particles as grass and it is going through my knife mesh

I was wondering if there is anyway to get rid of those few strands?

did you try selecting the particle system and entering edit mode to remove the particles?

i need to only remove those 3 - 4 strands of grass , not the whole system

have you tried it with the vertex groups and weightpaint?

ah i tried the particle edit and that worked perfect!

I used the particle Edit , And made sure i had the right particle system selected.

@SamirRahamtalla would you like to put that as an answer?

To remove particles select the particle system by clicking on one of its particles then enter particle edit mode by pressing Tab. In particle edit mode select the unwanted particles and press X to delete them.


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Weak normal map bake?
I have baked my high poly to my low poly , But the end result gives a very weak bump
This image is the low poly

this image is high poly
is there anyway to get strong bump maps?

BI or cycles? For BI increase the normal value in the texture settings and tick normal map in sampling. For cycles are you using a bump node or feeding it into the displace?

BI , but this is for baking, not the material

yes but after you bake the normal map you need to apply it to the low poly model. The settings adjust the strength of the normal map.

When looking straight at a model, there must be visible curvature on the model for the normal map effect to be visible.
I've illustrated this using several cubes and a 3D Viewport Matcap Normals' surface.  The view is top-down orthographic.
The cube at the top-left is just a default cube with no bevel.  It is invisible to normal mapping.
The top-right cube has only a very small bevel and it is barely visible in contrast to the plane.
The two bottom cubes were beveled enough so that the curvature across the top and side surfaces is clearly visible.


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Shadow catcher not working?
I have made a car model and i'm ready to render , I decided to try to make a shadow catcher plane ( which has never worked )
Im using and HDRI image and set up the nodes correctly , yet it still doesn't work.

This took me a long time to figure out. There are several Q&A posts on the site already that address this, you should check them out.

I have checked several times everywhere and nothing works.

I hate to say it, but you must be doing something wrong. If I can remember how to do this, I'll post an answer here too.

Gladly appreciated, I give up i don't know what is wrong

I'm guessing this because HDR backgrounds don't cast shadows on the shadow pass yet.

Troubleshooting tip. Pick one element that you think is the problem and remove (or substitute) it. This is a lighting related problem, start with changing the lighting. Disble the HDRI and just use a spotlight - simple, fast to test. Does the shadow catcher work? I'd also test another more complex light (hemisphere, sunsky) just to see if it only suports simpler lights.

Ok so getting rid of the HDRI makes it work perfect!, But the problem is i need the HDRI for the final render! What would be a work around to enable the HDRI?
Edit : I can enable HDRI , but it can only be seen on reflections! How can i make it visible in the background?

As said in the comments you cannot use HDRIs to cast shadows but the reflections are still showing up. You can't render the first layer without that transparent options else you won't be able to add that Shadow Plane correct? So here is my Solution:
For the first layer enable Environment Pass and then add it in the compositor like this: