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Trying to figure out UV Wrapping but it is not working
I thought for sure that I understood, but I guess I do not.
I "exported" - UV> Export UV Layout from the UV Editor, so that I could place materials via Photoshop to this exported layout - see attached image for the results - it's looks perfect to me, but the "shirt" obj does not refresh

I do not understand what I am doing wrong. From everything that I have read and watched, this is how UV Wrapping works
Screenshot of the material for the shirt - I gave the shirt a new material, as what follows what I have read

This was the original material, but it was not working. That is why I deleted it and tried to add a new material

Originally, I was hoping to fix the black box around the badge, which lead to learning about UV mapping.
You (@moonboots), I re-imported the obj file, then I just had to plug in the original material and Blender knew what to do. The following is the Shading area and the object that is correctly UV mapped - thank you all for your help

Here's the result and thank you:

Well, what does the material of the shirt look like? Is the texture you painted in Photoshop plugged in the material and is it using the UV map? Does the shirt even have a material?

Can you send a screenshot of the material of the shirt?

I have updated the post with the requested screenshot

You need to plug a Texture > Image Texture node into your Principled BSDF, and load the image in this Image Texture, otherwise Blender doesn't know it is supposed to project the image onto the surface

Added more context to my original question


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Increase floating point precision with large scene and parented objects
So I have a pretty large scene with ships flying towards a canyon, the ship has pilots in side but they are jittering around. I know this is a floating point issue but fixing it is proving hard.
The scene was massive (real scale) so I tried scaling it down, but it's still jittering. I've moved everything as close as I can to world origin.
You'll notice the scale is small so now the ships are around 1m in length instead of 30 odd, but if I go smaller the jitter gets worse. Is there anything else I can try? How do people do big scenes and not have this issue? Thanks

How are the pilots related to the ship? Are they animated independently? The ship, itself, is not  jittering?

I don't think you can improve this by descaling everything, you move your floating point, but precision is determined by float's number of digits. We had such a problem in our project in Unity. We solved it by fixing the camera to zero point and moving everything else instead. Jittering remains but only for farthest vertices, that can be mitigated by limiting visibility. But in blender easier could be to divide your scene to sectors and write a script that would move everything when camera approaches a boundary.

@RobinBetts Found my issue, I had parented the pilots to the hull bone of the ship, one character wasn't jittering and was parented to the ship object but not any bone, so I changed the way they were parented and it fixed the jittering. I wonder what the difference is? Thanks for reminding me to double check that!

"I wonder what the difference is? " parenting to different objects can differ based on the effect I call distant relative jitter (when a parent of an object is far enough away its jitter is transmitted to its siblings). Also, scaling will scale any jitter problems in proportion: it does not solve jitter, as @Vajtus indicated.

source: Stack Exchange

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

sort: votes


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masking objects rendered
I am using objects (those in image below) to mask parts of others (3D modeled holes in ground and wall) in camera motion tracking . Those masking objects are in different "background" layer, so they are not rendered in final image which is fine.
However, when I am watching the rendering process, it takes quite long to those masking objects to be rendered, so my question is, is there a way to let them only mask rendered 3D objects and not catch any light, to not be rendered at all?
I guess the process looks like this for each frame:

the 3D model is rendered (just the parts not hidden by masks)
mask layer is rendered (the one you can see in image below - you can see last three tiles to be rendered in bottom left corner)

In short, by those masking objects shapes (image below) I just want to tell Blender what parts of the 3D objects it should not bother to render. I don't need those masking objects to catch and bounce any light or so = don't take render time.
Using Cycles.
Sample rendered image - just masking layer :

@cegaton thanks for suggestion. edited, hope it makes more sense

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


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motion tracking timeline colors
I can't find the answer in online docs, or elsewhere. Would you know what the magenta colour means on the motion tracking timeline? There doesn't seem to e different amount of valid tracking markers, so no idea what this could mean, but it results in loose of track on frame 1393 (place where the magenta colour starts). Thanks.

EDIT:
One more image with another color following


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Understanding a UV Map/ How To Fix
I've been having trouble understanding why a UV map comes out the way it does and i'm looking for some help on how to fix it and understanding why the issue occurs in the first place.The issue that i'm having is that the UV's for the model are unwrapping in a distorted way even though the model itself is symmetrical. Heres the file if it helps. https://ufile.io/wf2ts
Thanks

you don't have enough seams so that it can unwrap properly, you need to add some seams on the top face and on a edge of each corner


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bpy parent chain without transform
How do I set an object parent without moving the child location as relative
Lets say I have an object relationship
- first
  - second
    - third

And I have absolute position/location/coordinates
first: 1.0, 0.0, 0.0
second: 0.0, 1.0, 0.0
third: 0.0, 0.0, 1.0

I read that we're supposed to use magic setter named matrix_parent_invert, like so
child.matrix_parent_inverse = parent.matrix_world.inverted()
so as follows is a quick script to do that, and my object positions remain relative with various order of operations of the following"
import bpy

first = bpy.data.objects.new('first', None)
first.location = (1., 0., 0.)
bpy.context.collection.objects.link(first)

snd = bpy.data.objects.new('second', None)
snd.location = (0., 1., 0.)
snd.parent = first
snd.matrix_parent_inverse = first.matrix_world.inverted()
bpy.context.collection.objects.link(snd)

trd = bpy.data.objects.new('third', None)
trd.location = (0., 0., 1.)
trd.parent = snd
trd.matrix_parent_inverse = snd.matrix_world.inverted()
bpy.context.collection.objects.link(trd)

expectation

reality

Since updating the View Layer can be too slow, here's how you would do it in a more performant way:
import bpy
from mathutils import Euler, Matrix, Vector

first = bpy.data.objects.new('first', None)
location = (1, 0, 0)
rotation = Euler((0, 0,0))
scale = Vector((1, 1, 1))  # Vector needed because of to_4d()
T = Matrix.Translation(location)
R = rotation.to_matrix().to_4x4()
S = Matrix.Diagonal(scale.to_4d())
M = T @ R @ S
first.matrix_world = M  # just using T would work but I wanted to show how to deal with rotations and scale
bpy.context.collection.objects.link(first)

snd = bpy.data.objects.new('second', None)
snd.parent = first
snd.matrix_world = Matrix.Translation((0, 1, 0))
bpy.context.collection.objects.link(snd)

trd = bpy.data.objects.new('third', None)
trd.parent = snd
trd.matrix_world = Matrix.Translation((0, 0, 1))
bpy.context.collection.objects.link(trd)

oh wow, you were not kidding about updating the view layer being slow. 3s -> 183s for a few thousand parents. oof

When you parent a object from interface, matrix_local and matrix_parent_inverse of the child object will change.
But setting the parent from a script without using bpy.ops, it doesn't change matrix_local and matrix_parent_inverse. So, you need to change them manually.
import bpy

first = bpy.data.objects.new('first', None)
first.location = (1., 0., 0.)
bpy.context.collection.objects.link(first)

snd = bpy.data.objects.new('second', None)
snd.location = (0., 1., 0.)
snd.parent = first
bpy.context.view_layer.update() # <--- important
snd.matrix_parent_inverse = first.matrix_world.inverted()
bpy.context.collection.objects.link(snd)

trd = bpy.data.objects.new('third', None)
trd.location = (0., 0., 1.)
trd.parent = snd
bpy.context.view_layer.update() # <--- important
trd.matrix_parent_inverse = snd.matrix_world.inverted()
bpy.context.collection.objects.link(trd)


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Object in edit mode acting weird - see through, knife tool not working right
So one of my objects and only this one, has this issue pictured where I can see through some of the mesh to the other side unless I zoom out a bit I can't see the behind edges, xray mode isn't on, but it's also glitching the knife tool out. It's like the position data for the edges are off somehow, it's saying the knife tool is connected but it's way off. I don't know how else to explain this it's all very weird. You can see in the last picture the knife tool is also ignoring the edges it's supposed to be cutting through on the right side.
I'm using 3.6, no editing plugins enabled.
I have xray mode off / face orientation is all good / it's non-manifold

It's difficult to tell from those images, but it sounds as if you have overlapping faces and/ or inverted normals. I think we'll need to see your Blend file. You can share it via https://blend-exchange.com/ following the instructions there to copy the link to it and then edit your question and paste the link into it.

@JohnEason Thanks, I've added a file with a part of the mesh, which is having issues, I've checked normals, overlapping faces, and even recreated the topology there from scratch, and the new geo has the same issue too.

Which part are you trying to use the Knife tool on? - It's still difficult to tell looking at your images and the various cuts I've tried have all worked ok. - I'm not sure what you used to model that mesh? Why is most of it triangulated?

Try scaling the object down to more typical size and opening the .blend file using default UI (file->new.., then file->open, click the gear it top-right, unselect "load UI"). The issue might be caused by the viewport clip start and end, though their range has the same orders of magnitude as the default range…

sorry, the straight part in the middle that's raised, it's trianulgated as it's going into a game engine, it's just very roughed out currently.
@MarkusvonBroady I tried scaling it down to 100m and 10m, applied scale and knife tool went even crazier. Oddly, if I zoom out the viewport and do a cut it seems to work okay, but it's really hard to see being zoomed out so far, if I try to zoom in that's when I can start to see "through" the mesh to other bits and the knife tool freaks out, no matter the scale or clipping distance. Blank / fresh UI didn't do anything differently.

@kaboose1066 you didn't mention that after scaling it down you also opened it with a fresh interface. Did you try that? also apply the scale (CTRL + A, scale)

@MarkusvonBroady yep I applied the scale and tried with a fresh interface, same result. Is the blend file okay for you? The extruded railing is the part with the most issues.

@kaboose1066 unfortunately I don't know how to reproduce your problem, it's not clear to me, so I just tried to help blindly... https://i.imgur.com/ryPGq9l.gif

@MarkusvonBroady thanks for trying, looks like I'll just need to zoom out a lot to make any cuts on my end, odd it isn't reproducible.


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Custom normals are not working in render, only in viewport
Using 3.6.0
My custom normal split geo data is working fine in viewport in render view, but when I go to render the image through the actual renderer it doesn't show the custom normals? Notice the diagonal line in the rendered frame. Any ideas?

Hello please show your shader editor

Do you have a Subdivision Surface modifier on the object with different Level setting for Viewport and Render?

@moonboots Heres the shader now added I'm using, I've tried removing the bump maps, even loading a basic BSDF and using straight colour, it does the same thing, so doubt it's shader based.

@GordonBrinkmann Nah no multi-res or any modifiers accept the armature.

Small update, turning off autosmooth does remove the weird diagonal line etc, but it also gets rid of my custom split normals, either way I can't seem to replicate the render look in viewport anyway I can. The degrees of the auto smooth stays greyed out on or off which is odd too.

FIXED: I don't know what changed, but the blender 4.0 release has fixed it. Might have been a bug maybe.


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Make explode modifer only appear if weight paint above threshold
(Update)
I seemed to have figured it out kinda, I've used an attribute node to drive the geometry alpha for the damage and destroyed geometry so the original nice mesh isn't touched but the destroyed appears over the top. The scaling isn't perfect as the destroyed meshes need to be slightly larger than the original and I can't figure out how to do that uniformly. But this is the result. I had to do this to each shader on each of the destroy and destroyed meshes.

Original Question:
I'm trying to make a space ship damage effect, using explode modifier with particleSystem and a cloth sim using an empty to control weight paint which drives where the damage is to happen. It works well, but the explode modifier is always visible and since it's slicing up the mesh it looks all weird.

Is it possible to have the geometry of the explode modifier only be visible when it's weight paint is above a certain threshold (since it's controlled by an empty)? So it only appears where the damage is happening, not over the entire geometry?
Or is there a way to make the explode modifier look not weird until pieces have moved?


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Blender 2.79b model export to Collada
I am trying to export from Blender to Collada .dae and seems that textures are not exported
Here it is a video with the steps
https://drive.google.com/file/d/11ELOeZovAhHoxm92P1poLjDk5EUdXZ8l/view?usp=sharing
What am I missing?

try to uncheck the "Only Selected UV map" checkbox

tried, same result -> no texture exported, only the mesh

here it is blender project: https://drive.google.com/file/d/1JESub-RWzdYmicfQB6IMWnuy6P4Iksli/view?usp=sharing

really weird. Copying of textures seems to only work if the image is selected under the in the uv editor when blender renderer is selected (even if switching back to cycles afterwards).

I'll try to make a small writeup as an answer after work if no-else already did it by then but for me setting the textures in the blender render worked. Both setting it as a uv texture and setting it as a material texture but not as a pure node texture.

The default Blender Exporter does not seem to be able to embed textures into Collada *.dae files (as of 2.79b).
It can however save textures alongside Collada files. To do that it has two sources of texture files.
Materials as texture source
See this video if you want to see it in action.
This is used when you select Materials in the Texture Options section of the Collada Export dialog.

The steps you need to make sure the texure is set, do the following:

Be sure that you are in Blender Render or Blender Game mode (you can switch back to another renderer after you set the texture)
1a. Select your object and go into the textures tab of the Properties Panel
make sure that you are editing the textures of the material
add at least one texture of type Image (you can add multiple textures and all will get saved)
set the image for the texture

UV Texture as texture source
See this video if you want to see it in action.
This is used when you select UV Textures in the Texture Options section of the Collada Export dialog.

The steps you need to make sure the texure is set, do the following:

Be sure that you are in Blender Render or Blender Game mode (you can switch back to another renderer after you set the texture)
Select your object and go into edit mode
open a UV/Image Editor panel and set the image you want to export as the texuture (you can switch back into object mode and this image will persist as the one that will be exported).


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Texture paint not showing in render mode
i made a texture paint for my model in Blender and saved it for later, i reopened my project added back my texture nothing special, i then started to work on adding pores with a alpha for the mask brush but it turned wrong and i couldn't erase what the "F Mask" brush did, so i closed and opened my work back but now for some reason when i am painting on my texture in the "Texture paint" mode, it wont show the changes in the render mode :

I can't figure this out my project is clean i have only one material named "Material.003" and one texture named "skintest" it started messing up when i tried to add the alpha pic of some pores to the mask brush by guessing...
If someone knows whats up please let me know,

If i move the UV texture it does shows the changes in the render but the Paint brush is ignored by the render...

Could you send a screenshot of your node tree?

There, hope it helps..

Ok so found out that i need to save the texture before rendering in UV/ImageEditor for the brush work to show up but i dont understand because i was able to paint in real time earlier, i even remade a texture so i am kind of lost, anyway i guess i am gonna have to work with saving between each stroke...


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Bump map painting brush problem
Hello i am trying to make a bump map but when ever i try to paint the brush gives me a ugly grainy look and i can't figure this out, i tried in a new project and it does the same thing
I checked for all those things but nothing works...

When you created your image texture in the UV Map area did you choose a high enough resolution?

Do not plug blue output socket into grey input socket. It might work the other way around but definitely not this way. In your case do not plug output of Bump node into Displacement input - if you want bump then plug output of Bump node into shader (Diffuse, Principled, whatever). If you want displacement then use output from image node (and ColorRamp / Math node to control it)

For the resolution i did 1045x1045, 2000x2000, and 10000x10000 and all have the same grainy look and for the nodes i did use a shader between bump and output before and i have the same result i added new pics for proofs, the problem lays elsewhere...

The problem will be present if you use node inputs and outputs wrongly. There probably are other problems but why not solve this one first? What did you try to prove with new screenshot of Glossy shader plugged into Displacement input socket? Indeed it will work as crazy as it does but it only shows what I mentioned in the previous comment - do not plug data from neither blue or green output sockets into grey input socket  - it will never work this way. See https://blender.stackexchange.com/a/102521/1245

Yes it was indeed the issue i did mindlessly this node configuration following this tutorial          https://www.youtube.com/watch?v=ktsyL2Kp5bQ&t=610s  i dont know if i did it wrong but i did it back the simple way as Nathan told bellow and it worked perfectly Thanks a lot !

I'm just rewriting this whole answer i response to your edits, which reveal that the problem is with your node setup.
There are two (or more) ways to do one bump.  One is to use the displacement output with a material with bump displacement enabled.  The other is to use a bump map node to distort a normal and feed that into a shader.  Usually, not both (although there can be times for that as well.)
The easier, more typical way to do it is via displacement output.  Displacement expects a value.  Not a shader.  But you're plugging the output from a glossy BSDF into displacement.  That doesn't make any sense.
Here's proper node setup for bump mapping.  The image is 32 bit, which I recommend for bump textures, and I've just drawn manually, in UV edit paint mode, with brushes at default settings other than size.  Notice that to modulate the bump map, I've run it through a multiply (math) node, rather than using a bump node.  Although it can be a bad idea to run nodes from color to value, here it's fine, as it's just a grayscale image.

I AM working in Cycles and i did put the image in non-color data, i tried to check the 32 bit float and i guess it did look i a little better but sadly it is not the problem and the zoom has nothing to do with this because it is grainy in every angles and with any resolution of map oddly enough it seems that some faces looks better (see edit) but it is still ugly, thanks though :(

See edit made in light of your new screenshots.


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Can't See Background Image on Ortho View
I'm trying to import a background image, and it shows the file name, but it does not show up. I put it in Ortho view but it still wouldn't show. I tried with lots of images just to make sure the image was corrupted or something.
Any ideas?

Can you add a screenshot of 3d view and background image panel?

make sure, that the viewport view matches your view setting of your background image, so both top for example

Do note that background image will be visible only in preset orthographic views (Numpad1, Numpad3, Numpad7). See http://blender.stackexchange.com/questions/118/how-do-i-set-a-background-image-while-i-am-editing

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


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Mesh being deformed in a weird way by armature
I made a low poly mesh by using skin modifier on a skeleton kind of shape made out from extruding vertex from a single point. After that, I applied Subdivision Surface and Armature modifiers to bring everything to life.
It worked fine, I did some improvements with IK bones and nothing fell out of place, I made a little idle animation and it was fine. Tested exporting it to Godot but didn't do much after that, as it was late at the time, saved and closed the project.
Now I open the project, 3 days later, and notice something odd about the wrists, they have a weird looking deform that wasnt there on Friday, guess its just something about the pose and I try to switch it around, more weird things start to happen.
Joints deform as if they had a cylinder blocking their path and thighs have a small jump as wrist have.
I've tried googling but to be honest, I dont even know how to word this issue, I've tried fiddling around with the weight painting but to no avail, as well as switching Armature modifier's Bind To from Vertex Groups to Bone Envelopes, and it actually made things worse. I removed every Vertex Group from the mesh, and applied the armature again With Automatic Weights, this fixed some issues but some parts of the hands and feet were stuck without being able to deform.

It deforms oddly on joints, wrist issue can be seen

Weights seem to be as they should, nothing visibly out of place.

While in edit mode, everything seems to be normal

Same issue is present on knees

The issue extends throughout the model
Even though it wouldn't take me as long to redo the model, I would like to keep the current one and figure out how to fix this, as if it happened once, it could happen twice and on a more complex mesh.

Even after deleting IK targets and poles and re-parenting the armature With Automatic Weights some issues were present, and manual weight painting didn't fix them.

Could you upload your blend file file here blend-exchange.giantcowfilms.com so I can try to help you?

All done! My bad for the delay https://blend-exchange.giantcowfilms.com/b/4992/

You have too much influence on the other side of the joint.  If you remove some or all of the bone weight on the vertices opposite of the joint, you should see this particular issue mitigated.
However, joints that bend over 90 degrees or have complex movement are difficult to rig in general.  You can mitigate this some with topology that takes the movement into account, see this polycount wiki for examples: http://wiki.polycount.com/wiki/Limb_Topology
Your character seems to be designed to be somewhat...noodly... so you might want to consider having an elbow bone to smooth the bend and preserve that style.

The extra bone at the bent.


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How to import AC3D files?
Using Blender 2.66 with Ubuntu 13.10.
How to import AC3D files?
I do not see an option for this under user preferences.

You can use majic79's Blender-AC3D addon. It is a port of the one that existed for Blender 2.49 and the author seems to update it every now and then.

What is it?
  It's a few python scripts to import/export AC3D data into and out of Blender 2.63+. For earlier Blender 2.6x versions you need an older revision of the plugin (https://github.com/majic79/Blender-AC3D/tree/BL2.62)
Known Issues:

Exporter:

Export packed .blend images is untested...
It will either export everything, or everything that's selected. Default
  behaviour is to export everything, if you want to only export those items
  that you can see (ie, in the render scene), then select all those items and
  check the "Selection Only" option on the export dialog.
There's an option "Export Render Layer" - ie, only export what's currently
  visible - this doesn't work, but is in the plan

Importer:

No ngons yet.

Thanks for reply. The addon noted above does not function with Blender 2.66

@robgrune It is working for me in the latest build of Blender 2.69. Did you follow the instructions? Try searching ac3d after putting it in your scripts folder. https://i.sstatic.net/NItKB.png

Thanks for reply. I installed again. Followed directions in readme file. The key is to find the blender scripts addons folder with root permission, so to put the ac3d folder into the addons. Then configure Blender preferences to add the import/export function. Now working. Great!

I have a fork of this project running in Blender 2.80 https://github.com/jentron/Blender-AC3D import works, but as of today export does not.

The Majic79 github has become inactive, the import-export script is still being maintained however. It is tested with Blender up to version 2.79, with many bugfixes and more complete format compliance.
It can now be found here: Blender-AC3D add-on.
And here for 2.80: Blender-AC3D 2.80 add-on (beta)

This add-on was updated to 2.80 Stable today, it can be found here https://github.com/NikolaiVChr/Blender-AC3D/tree/2.80

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


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Curve guide on linked object
I am linking in a rigged character to another file. But I cannot seem to get the "Curve Guide" physics to work for the hair of the character.
Some bones of the rig controls some empties that in turn works as hooks on a curve.
Finally, the curve is enabled as a "Curve Guide" which controls the movement of a hair braid.
The problem is that the curve guide does not seem to be working when I link in the character in another file. I have made the rig a proxy and I see changes in the curve placement when I move the bones, but the hair is unaffected by the the curve guide.
Is there a way to get this to work? Preferably without making local copies of things.
Note: In the character file everything work as intended. It is when I link the group containing the character, the rig, the empties and the hair emitter that I run into problems.

Particle systems can't be linked into a scene dynamically. So you can't change the shape of the hair from what it is in the original file. You'll have to append the emitter as a local object.
An alternative, for braided hair that could work well, is to model the braids as a mesh object with either particles wrapped around it or a texture. Then use the curve guides+hooks+armature proxy system to animate that.


text:
What are the Cycles specific Viewport Display settings in the material tab good for?
The material tab contains a Viewport display panel. Here you can set the color to display a mesh in green in solid mode for example.
But there is also a Setting sub panel. And its content does simply nothing in the viewport.
Is this panel for Cycles in the wrong place? Because with Eevee these settings are in the Settings tab.

Wow! I had no idea these settings are accesible through the properties panel, this is great :). I always switched to Eevee to adjust them.

@JachymMichal Same here... I think the location of these settings is unfortunate...

Moreover, you can't access it under the viewport display settings if you're accessing it from the shader editor in the N-Panel...

@Gorgious Exactly :). No idea why these settings are missing in the Shader editor, seems like an oversight.

In case you want to try, this could be something for the papercut thread at blender developers. https://devtalk.blender.org/t/blender-ui-paper-cuts/2596

If your 3D Viewport Shading mode is set to "Material Preview", then these settings become relevant. For example, if you have a glass material and set the Blend mode to "Opaque", it is not transparent (just like in the render settings for Eevee).
You can change Eevee settings there, without switching render engines.

What shading mode do you mean? We have four viewport shading methods :)

Yeah, of course... I meant "Material Preview", I'll edit my answer.

Ah thanks buddie. Now it makes sense :)

I guess the same counts for the eevee settings then?

Well, not exactly. In Eevee you don't have those specific Viewport Display settings. It just uses the regular settings that you've shown in the second picture.

It seems these are actual Eevee material settings. Just so you don't need to switch back and forth to adjust Material Preview :).

Indeed. It's the same operators in the same python file.


text:
Is it possible to extrude a curve in two directions?
I want to extrude a curve in two directions.

Or join both curves into one, is it possible? I've tried copying it and then join segments, but I don't see Remove Doubles option while working with curves.

There is the Split option in the Curve menu that's available in Edit mode. I believe it just joins another curve to the current one, though.

Not supported in Blender, curve vertex must always belong to a maximum of two segments.
Either use a mesh object with a Skin modifier instead, if you require true 'branching' and a continuous mesh surface.

Or if you prefer curve objects duplicate a vertex in place, leave it overlapping the original one, and then extrude the new one; if you don't mind the discontinuity in the mesh.

You can just directly select any middle vertex and extrude it twice with E, the first extrude will duplicate the vertex automatically Right-Click to cancel and the second extrude will start a new branch.

I have posted a question maybe similar to this answer. A pop box arise before extruding and the new extruded curve is that connected to the old or we have to connected and how. http://blender.stackexchange.com/questions/77375/how-to-make-branch-from-bezier-curve

It is not connected to the previous branch, that is not supported in Blender


text:
Can you easily make an edge loop go through a triangle?
Is there any way to do something similar to Maya's insert edge loop tool, where the edge loop wraps around the triangle? (Using Ctrl + R makes the edge loop stop before the triangle)

I don't think this function is built in, but I guess you could always Knife Project an edge through the mesh.

Yeah, I am aware of the knife tool but I was looking for something more convenient, like this Maya tool so you can do all of the steps in one place.

Knife project is a little different from the knife tool, you can define a shape and then use that shape to cut all the way through something with respect to the current camera view (ortho or perspective)

I see. That's also a great alternative

In wireframe mode you can select easily all the edges what you want to cut at once.
To create the new loop on them select Edge>>Subdivide.
Now you can adjust the number of cuts on the bottom-left.
If you want to move them, select a loop and double hit "G".
To create more loops after the move, select a loop and choose
Edge>>Bevel Edges.

Great! Thanks =)


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Darker weight paint colors (Blender 2.8)
Weight paint from Blender 2.79 (shown in Blender 2.8)

Weight paint created in Blender 2.8

Is this a problem? Also, if not, is there a way to change it back to the neon colored weight paint so that I'm able to see it better?
EDIT:
I tried tweaking up the custom colors, but they are still dark.

It's not so dark for me I don't know the reason why yours is. But it is adjustable you will find a colorramp for it in the preferences.

May be you messed up something here:

The colors are still dark.

Oh, yeah. I switched the color to object and it works just fine. Please edit your answer explaining the solution before I count it as solved.


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what is and how can i stop the constant "canceling..." in the compositer?
At the moment I'm working on a project and I was using the compositor. I don't know what started it, but at the top of my screen, there is a bar that constantly says "canceling"
also, my render layer node outputs are flickering

I'm making a graphics design thing with animation nodes, that's what you can see in the compositor. I 'm trying to put a vintage noise over it that's what you can see playing in the top.

and next to that my compositor is very very slow.
I have tried a lot of stuff to make it go away. I have restarted blender, I have reinstalled blender and I have tried to remake my whole node setup. but nothing works. the only way to make the "canceling" go away is closing the composetor window. but the moment I open it again it comes back.
I really hope someone can help me with this problem

Without knowing your node setup and settings it will be very hard to determine what the issue is

I've been having this issue as well and came to the conclusion that (at least for me) it has something to do with the animation nodes even when playback is stopped. It cripples my ability to render until I delete the animation nodes and have yet to find a work around. .blend linked as examplecancelling loop

In Animation Nodes, Disabling "Always" under Auto-execute fixed this for me.
Same issue as you, in Compositor constant "Canceling.." in the status bar. Viewer was absolutely broken and would not update plus that flickering issue you described. Seems like if AN is set to always try and solve it's nodes, it conflicts with Compositors ability to update.
Frame Changed, Property Changed & Tree Changed seem to be fine to keep active.
Also Viewer nodes (in animation nodes) don't seem to cause issues either.

I was able to get it to stop by deleting the viewer node from my node group in the animation nodes add-on. I was using a viewer node to confirm my output was correct when sending some text data. From now on I know just to use it to check and then delete it. Probably has something to do with the viewer node also being used in the compositing tab?


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Material persists even after being deleted
I created a Blender Render material and added color, after that i changed to cycles render and selected use nodes, now material color persists even after deleting the original material so any material i apply result in a darker color than when i apply it to new objects.
It is as if the original color had been baked to the mesh so now it´s darker than normal even if i remove all materials from it.
I may have done something else but i can`t recall, i deleted the automatically generated data in node editor (Material and Out, still in blender render)
Im joining now the original mesh with a new one and it is always bicolor, i can change color by applying a single new material and works for both pieces but the new mesh is always lighter than the original one.

I'm rather confused. What render engine are you using now? (and why did you switch?) Does the render have this ghost color, or just in the view port?

Hi, i´ m using cycles render now and i noticed that in Material view the new material is showing and also rendering but when i go to solid mode i see a bicolor mesh, still i don´ t understand why.
i really messed with it because i thought at the beginning that i was on cycles render but when i tried to appl a material i notices it was different, but i didn´t knew why at the beginning, so i started clicking everything and like creating materials, deleting nodes. so that´s also why i changed because i was trying to work on it since the beginning.


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Geometry node collision issue with fast projectiles
So I have a geometry node set up that fires instanced geo of a bullet, and that bullet on collision with a mesh explodes into particles, all works well up to a certain speed, but not the speed I need. The projectile starts to clip through the collision geo and not trigger it's particle sim on impact at a certain speed, instead it doesn't register and goes through it completely. The fire rate and other parts of the scene are tide to the frame rate so I don't want to increase it from 24, unless theres a way to do that without messing other things up?
Is there a way to get subframe simulation in the geometry nodes sim area? I've heard something about the repeat node potentially helping but I can't see how. Any ideas?

It won't be easy but you could, at each frame, repeat X times : move object 1/Xth of a frame > test collision (if yes trigger other things, else repeat). Basically it would be a custom implementation of substeps.

First of all, if the bullet is small, just test the collision using raycasting from old position to new position. But if the bullet is big enough for you to care about its shape, and if the bullet is convex (probably is, or you can treat it as if it was), then you can do a convex hull of the bullet in old and new positions joined together, as I do here: How to make object cut into another object and leave a hole behind?

@MarkusvonBroady Yes the geo nodes are using raycasting currently, I've added an image of the collision nodes, the particle technically triggers the collision I guess? But the particle fx spawns at world origin instead of where the collision happens at the higher speed, would that still suggest an issue with the collision of something else? Slower speeds the particle hit happens where the collision hits but faster hits trigger the particle hit at world origin.

We can't really help if you don't produce a minimal working example and share it...

Sorry being a paid addon I didn't want to share it, but I have fixed it, turns out the raylength of the raycast for instancing objects onto surface was too low at the base 10m, increasing it to 100m fixed it. Thanks for the idea of where to look!


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Dynamic paint on uneven surface
I am trying to animate a ball rolling through a desert scene, leaving a trail behind it. The intention is for the ball to move along the surface of the plane rising and falling with its ridges.
In order to accomplish this I have attempted to use dynamic paint along with the shrink-wrap constraint.
When I attempt to make the ball follow a curve, dynamic paint does not appear to have any effect at all. When I add key frames, a trail is left that adheres to these but does not follow the shrink-wrapped path.
As a workaround is it possible to keyframe the shrink-wrap path?
Am I perhaps approaching this from the wrong direction? Please forgive my lack of blender prowess.

A similar unanswered query can be found here: How to use dynamic paint with constrained objects
.Blend:

So provide your blend file so we can check it out…

It's looks like the ball rolls in the air without touching the surface.

Apologies, I've added it now @Chris

thanks! Hint: if you include blend files in your question, you will get better and quicker answer...and the probability that someone is willing to help you increases ;)

Just select your plane, increase the substeps to 1 on your dynamic paint:

hit bake...and you get:

I had completely overlooked the bake button! Thanks so much for your help

You are welcome!


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How to transfer cloth simulation from one mesh to another
I want to animate cloak for my character by using separate mesh(low poly).

And then apply to my cloak through deform modifier. Every thing is working.
But how can I bake this deformation modifier with simulation into my actual model?

Video:
https://youtu.be/V-3TPf8ql0M

Why do you want to "bake" modifier? That is your goal?

I want to export full animated character into another soft. To be more precise, the site - sketchfab

Well, it was much easier than i thought. I used mdd and everything worked.
if anyone is interested here is the link:
https://youtu.be/AEP2RgaBGlk

Then preparing animation to an external software for you have to know, that end platform can support. According to documentation, sketchfab can play only this type of animations:

Solid animation: translation, scale, rotation
Skeleton-based
animation: model rigged with bones
Morph targets: transformed vertices
(Shape keys)

As you see, it can't play Blender's modifiers nor Blender cloth (and others) simulation.
Also in the documentation you can see, that it supports Timeframe (Stop Motion) animation. In this case, you can export animation into OBJ sequence:

And use the workflow described here

May be somebody know more accurate or effective method of animating it. My problem, why I won't use cloth sim directly on the model, is that it has thickness


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Shader/UVs in Eevee looks different in Cycles
I am working on a timer (based on a tutorial by CGMatter), and everything works when I view it in Eevee Rendered view, but when I switch to Cycles, it appears like the shader just stops working, the UVs also appear like they are not transformed anymore like they are in Eevee (see images and blend file below). Does anybody know a solution for this?

Eevee Rendered View ^^^

Cycles Rendered View ^^^
Here's my blend file.

Eevee and Cycles are 2 very different engines where cycles works with light bounces and Eevee approximates everything to make it faster... This way you are missing the Bloom effect that is easy to setup in Eevee, if you want the Bloom effect in Cycles, you need to go to composition and add Glare node with Fog glow as an option... for 5 changing to 0, I am not sure because I don't know how are you changing it, is there a way you can share your file?

Thank you for your comment, I've now attached a blend file (not sure if it works for you because I reckon it requires the image texture as well), you can view the difference when you switch between eevee and cycles, everything with the numbers is basically happening in the shader section.

You forgot to pack textures, go to File > External data > Pack all into .blend and send it again or send textures as well

It should now be updated.

The bug is caused by Material Output node that sneaked its way to the custom node group:

Apparently Eevee and Cycles resolve the conflict of multiple Material Output nodes differently. Removing this node from your custom node group solves the issue.

Aah there it is, I was wondering why there is visible material even when I disconnected material output from any values... didn't saw that there is second output

Aha, I see, thank you so much, I have been looking for a while to resolve this issue.


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Dragging center point of cube won't drag all edges to corners with it
I'm so sorry if this is a horribly asked question but I am very new so I do not know all the terminology yet. I however do have pictures so that I can show the problem.
What I have now:

What I want is instead to have the left and right corners to form edges like:

But right now that only happens to only 2 of the corners. How do I get it to drag all 4 of the corners when I translate the center vertex?
EDIT: It appears the corners that this happens will change depending on my shading
Rendered:
The corners that do not follow are next to each other now.
All others: Above, opposite corners

The problem is that your faces are non-planar (read this) and therefore need to be converted to triangles to be displayed (Blender will do this without telling us).

Showing us the render wires, make the triangulation apparent.
It is possible to trick Blender into triangulating the nonplanar quads in a different order.

Remove the faces in question and recreate them with triangles.

Select the adjacent faces in the correct order and join them with ⎇ AltJ.

Note, that the correct order is dependant on the vertex index which can be shown only with debug options enabled.

But this is not useful. If you want the area to have an edge explicitly define it with the correct topology.

In the reference video, the same behaviour occurs.

Thank you very much! However I was wondering if it was possible to make it default to the different order? For example, this video shows that he could simply transform the vertex without needing to add edges or trick blender.

@Vuninja Check out the last edit.

I found a work around which is to just connect vertex path (Ctrl+V -> C). If anyone else has a better solution as this adds more edges, please answer.


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body mesh clips through armor mesh, mesh not taking to bones
Ok so im a big noob on blender and i imagine this has to do with weights but i feel ive gone through every avenue to solve this issue and cant find anything on this. I have a mesh Ive tried to attach armor to, and it takes but the body under the armor acts like the armor doesnt contain it. heres an image on UE4 of what i mean.
As you can see the shoulder just sticks out, in reality (so to speak) the armor should bend with it like rubber. Now i didnt make the armature myself i imported the mesh into mixamo and then opened it in blender. originally mixamo didnt like the armor being in the mesh and would curve its shoulder wings of the armor with the arm movement. To fix this i removed the armor and re imported back into mixamo. it worked great! now im putting the armor back and the results are better but now im getting the body mesh peering through the armor like shown in the image above.
In blender i append my armor. then i joined it to the body mesh. if you look at the outliner in the pictures below you can see what was done.

so im able to move the mesh in pose mode and it wont effect the shoulders which is good, and the fbx shows the armor on him in ue4 but i cant figure out how to contain the body in the armor, id also like to keep my bones if possible, i want to use the mixamo animations. If i could just get some assistance or even a nudge in the right direction, id appreciate any help i can get. if you need more i can upload the blender file just ask.
thank you to whoever reads this :)

You need to weight the armor to the bones.  The quickest (not best) way to do this is with a data transfer modifier, transferring vertex groups, probably on the basis of nearest face interpolated.  From your pic, you may need to position the armor correctly first.  If you weren't doing it for UE, you could get a good approximation via a surface deform modifier instead.

Thanks for the response Nathan. I will look into the data transfer modifier, however like I said I'm a noob and i have no idea how to use that modifier lol, also I realize in blender the position of the armor looks strange, if I select the body mesh and change to edit mode the body changes position to where the armor is in the picture, if that is an issue i would like to know how to fix it. Other than that i figured it was positioned correctly. I could be wrong :)

It's fine to be a noob.  Maybe you've bitten off more than you can chew.  For right now, the important thing is that you start learning about weights and vertex groups, which are what you need to make the armor move correctly.

Ok I bought the course for blender on udemy. I'm going to look up weights and vertex groups there now and see what I can figure out. Thanks alot

Oh actually one last question. If I make a vertex group in one mesh (the armor) and join it to the other mesh (body) to make one mesh, will the vertex group in the armor still exist?

"Oh actually one last question. If I make a vertex group in one mesh (the armor) and join it to the other mesh (body) to make one mesh, will the vertex group in the armor still exist?" Yes.


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Edge selection highlight not working
After updating to 4.1 I stopped seeing selected edges when more than one is selected.
In this gif you can see I am selecting 3 edges. The first one behaves as usual, but when selecting the second and third one, the previously selected stops being highlighted, although is still selected otherwise I could't move all 3 at once.
I have a RTX 3090 with up to date drivers if it helps to discard visual glitches

https://ibb.co/q1K2q77
Anyone else?


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Issue with posing after resizing
I'm working on animating a person climbing a building for a school project.  I have the rigged character and the model for the building, but the model for the character is far too large.  I used the scale tool to scale it down to the proper size, then began to model.  After I moved the first bone, what looks like a large blob appears under one of the character's feet.  This disappears if I go into edit mode, but is visible in object or pose mode in both solid and rendered view.  Any help would be appreciated.

Can you upload your blend file and also some screen shots so we can see just what you're experiencing, since this problem could be caused by many things. If you need a place to upload to, you can use PasteAll.org -- it's very easy to use: http://www.pasteall.org/blend/

I found a model that worked better for what I needed anyways and I'm not having the problem anymore.  I'm still interested as to what the problem is, though.  I posted it to http://www.pasteall.org/blend/28205.  The file name is error.blend.

If the answer below solved your problem, don't forget to click the "Solved" checkmark to let everyone know the question has been solved. :)

Apply Object Transformations When Rigging
The problem with the figure's foot is that the scale of the figure and the scale of the rig are not both equal. This can cause unusual behavior like what you experienced.
To prevent this from happening, whenever you are joining a rig to a mesh, you must first always apply their scales so the scales are both set to 1.
The reason for this is simple: when you import a figure, it will default to have a scale of 1. Also, when you add a rig, it too will default to a scale of 1.
However, almost always the figure and the rig will be different sizes, so you naturally will change the scale and maybe even the rotation of one or the other so they match up and the rig fits right inside the model.
This results in a difference of scale (and maybe rotation) of the rig and the model. In your file, the figure's scale is 1, but your metarig's scale has been reduced down to 0.195:

(You can see the scale of objects in the Properties panel, which can be opened with N)
This difference of scales becomes problematic when the rig is joined to the figure.
Therefore, whenever you finish scaling and/or rotating both your figure and your rig, you need to Apply Object Transformations to both the figure and the rig. When you are Applying Transformations, you can apply the location, rotation, and/or scale.
Here is how you do that, first for either the rig or the figure, then for the other:

In Object mode, select either the rig or the figure
Then use one of these methods to apply transformations:

3D View Header -> Object -> Apply -> Rotation & Scale
CTRLA -> Apply Rotation & Scale

The main goal is to have the Rotation for both rig & figure set to 0 for X, Y & Z, and also to have the Scale for both be set to 1 on X, Y & Z.
Then your rig will work properly.


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How to create single-pixel wide edges?
When using the Edge option on the renderer, it creates several-pixels wide borders.
on blender http://dl.dropboxusercontent.com/u/62862049/Screenshots/01k.png
When creating pixel arts, though, it is fundamental never to have 2 black pixels in a row:
somewhere else http://dl.dropboxusercontent.com/u/62862049/Screenshots/01j.png
How to achieve this effect on Blender?


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Error: File format is not supported in file
I made a simple sphere in blender, since Ursina doesn't support UV maps. When I tried launching the game, I got this:
*found blend file: C:\Users\nadja\OneDrive\Dokumenty\GitHub\pratformjump\assets\skymodel.blend*

*blender_version: 3.0*

*converting .blend file to .obj: C:\Users\nadja\OneDrive\Dokumenty\GitHub\pratformjump\assets\skymodel.blend --> C:\Users\nadja\OneDrive\Dokumenty\GitHub\pratformjump\models_compressed\skymodel.obj using: C:\Program Files\Blender Foundation\Blender 3.0\blender.exe*

*Blender 3.0.0 (hash f1cca3055776 built 2021-12-03 00:44:02)*

*Read prefs: C:\Users\nadja\AppData\Roaming\Blender Foundation\Blender\3.0\config\userpref.blend*

*Read blend: C:\Users\nadja\OneDrive\Dokumenty\GitHub\pratformjump\assets\skymodel.blend*

*Error: File format is not supported in file 'C:\Users\nadja\OneDrive\Dokumenty\GitHub\pratformjump\models_compressed\skymodel.obj'*

```

Hello ! The error comes from your game engine or from Blender ?

@Gorgious game engine

@Gorgious also its Ursina i forgot to mention


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Ctrl+Right click is not extruding vertex to mouse but rather on top of the selected vertex
Vertex select is on and it's properly making new vertices but it's just making them on top of the existing one rather than to my mouse, any idea why this is? It works in other projects, and I've tried load factory settings and then open without loading UI and still no go.

Edit: If I add a new cube in the project I can extrude it just fine, it's just the original object that doesn't extrude properly. I can still grab the vertex and move it that way though.

I figured it out, my scale in the Z direction was set to 0. While I was only working in the x/y dimensions, having 0 scale broke the mouse from working, even when the camera was perfectly set and orthogonal.
To fix: Go to object mode, press 'n' to open the Transform options on the right-hand, make sure Scale isn't set to 0. If you set dimensions to 0 it can set the scale to 0 as well.


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When I move selected nodes from a cylinder to bend it the edges seemingly randomly splay out everywhere
images of the problem:
The cylinder before being moved:

After moving the central loop on the x axis:

From a different angle:

Want do you want to do exactly and what did you do to get to this result (what shortcuts)?

I want to make the cylinder lopsided in the middle by moving the loop to the side

I grabbed the loop and moved it on the x axis to move it over.

I am following the donut tutorial this is the link: https://www.youtube.com/watch?v=bLw0HwphXO0&list=PLjEaoINr3zgFX8ZsChQVQsuDSjEqdWMAD&index=10    Timestamp: 3:49 - when he is making the sprinkle bended

Maybe try disabling snapping to face.

thanks a lot :)

That solved the problem

When you select the edge loop, you're only going to be moving those edges, so of course it'll warp the shape. You're in Edit mode. If you want to get back to Object mode, hit tab.

How would you recommend I stop the warping

I am following the donut tutorial this is the link: youtube.com/…      Timestamp: 3:49 - when he is making the sprinkle bended


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How do I batch convert material assets to group node assets?
Since blender 3.1, it is now possible to create group node assets, making it easier to group shaders and reuse them.
However, most existing assets (blenderkit, ambientCG, etc.) are materials, not group nodes
Once the material is applied, grouping is easy, but time-consuming, as previews must be set manually.
[Question] Is there any add-on that allows batch group node conversion of material assets?

[EDIT] My idea of workflow
Preparation

Drag and drop material assets
Group all nodes except for the material output and Mark Asset.
　(Surface, Volume, and Displacement will be the output node groups)
Manually set the preview image of the asset in the group node

Use

Drag and drop group nodes and connect them with mixed shaders
Shaders can be partially reused, e.g. painting textures for fac.
https://i.imgur.com/xMcnp6e.mp4

Is there any add-on that simplifies this preparation part (1-3)?
This is a question.

Hello, could you add a diagram explaining more in detail the workflow you're looking for ? Materials and node groups are different in essence, what inputs and outputs do you expect from the action you're looking for ?

@Gorgious Thanks for the response. I have added my idea of the workflow.


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How to create a simulation in Geometry Nodes pre 3.6?
UPDATE: Simulation nodes are now available in B3.6β!
In the recent week the Blender community became crazy on the particular geonodes hack, that allows you to create a simulation in Geometry Nodes alone:
 NENGHUO on Youtube: Breakthrough! !" For Loop" in the blender geometry nodes.
 GifCo on Twitter: Geonode simulations are all the rage these days!!
 Default Cube on Youtube: FINALLY! NEW Loop Node
 Seanterelle on Youtube: Geometry Nodes Differential Growth Simulation Tutorial
This is not a forum to vent one's frustration, so let me just say a better¹ technique exists at least since I started using GN in Blender 3.0, so I decided to share, in Q&A fashion. Everyone is welcome to post his alternative technique - perhaps one involving physics - I've done something very limited in geonodes+cloth here:
 Create Curve from Path of an Object Using Geometry Nodes
¹ - Maybe some people hate Python so much, they would rather use a dirty hack relying on Blender failing to protect from circular reference, which can hang the program, is not officially supported, is not a designed feature: exists in memory only as a temporary evaluated object without any representation in .blend datablocks, therefore can't be saved or maybe even restored with ✲ CtrlZ undo [not sure, haven't tested], runs an erratic number of times (I think on each depsgraph update?) and so runs in a single frame rather than with one step (or a fixed number of substeps) per frame, and can stop working (be fixed) in future versions of Blender.

This is a very interesting Q&A ! However I would have replaced the "python" tag with the "simulation" tag. Tags should describe the question, not orient the answers. I'm sure non-python related answers have their place here and the tag might refrain people from exploring them. Just my 2 cents :)

@Gorgious good argument, I removed the [python] tag, and I agree in regards to the simulation tag, except there is no simulation tag! So when I wanted to add one, I saw instead 5 tags to choose from: [fluid-simulation], [cloth-simulation], [smoke-simulation], [ ocean-simulation], [rigid-body-simulation]. Do you think I should jast add fluid, cloth, smoke and ocean variants, as the rigid body one would actually be tricky to do in geonodes?

hehe I didn't know there wasn't a dedicated simulation tag :/ I'd say cloth and rigid body are good candidates, but in the future I can see all the other ones being possible :)

Not just simulation itself ? Useful for procedural geometry/ textures which are the result? eg the results  of growth, erosion, flow .. etc

@RobinBetts define "simulation" - in the context of Blender I believe it's basically exactly that, it's a continuous process relying on access to previous frame data. I think your examples fit well into the existing pool of simulations like fluid and smoke.

Geometry Nodes are planned to support a simulation out of the box one day:
 Geometry Nodes Post BCON22 Workshop
Meanwhile, you can use a Python script like this:
import bpy
from bpy import context as C, data as D
from bpy.types import SpaceView3D

loop_mapping = {
    'single vert B': 'single vert A'
}
evaluated_frames = 0

def simulate():
    global evaluated_frames
    if C.area.type != 'VIEW_3D':
        return
    # hard-coded to start at frame 1
    if evaluated_frames + 1 != C.scene.frame_current:
        return
    dg = C.evaluated_depsgraph_get()

    for ob_from_name, ob_to_name in loop_mapping.items():
        me_from = D.objects[ob_from_name].evaluated_get(dg).data
        ob_to = D.objects[ob_to_name]
        me_to_old = ob_to.data
        ob_to.data = me_from.copy()
        D.meshes.remove(me_to_old)

    evaluated_frames += 1

try:
    SpaceView3D.draw_handler_remove(SpaceView3D.my_handler, 'WINDOW')
except (AttributeError, ValueError):
    pass

SpaceView3D.my_handler = SpaceView3D.draw_handler_add(simulate, (), 'WINDOW', 'PRE_VIEW')
C.scene.frame_set(1)
bpy.ops.screen.animation_play()

This script is simply evaluating single vert B, and saving it as single vert A's mesh data on each frame. You can add more object pairs to the mapping. You can build on top of this technique by for example not removing the old mesh data me_to_old and setting each mesh'es name to end with the frame number it was evaluated for - this way you could add another check to simulate, that restored one of the already evaluated meshes if a frame was already evaluated (current frame < evaluated_frames+1). You could also program in substeps, which would simply loop the part that evaluates an object and moves it to the other object, and you could add any arbitrary Python shenanigans. Some of those techniques I teach here:
 Distributed interaction visualization
On the geonodes part, Create the two objects, and for the single vert B (the former in the mapping pair, the dictionary key) add your simulation logic:

This example is very simple just to present the point: Sample the noise texture at current position, offset to be on average 0 (so the sphere you will see in a moment is less likely to run away), normalize to ensure the sphere actually moves, and use a switch to really ensure the sphere actually moves in case a $(0, 0, 0)$ vector was produced. Scale it, because $1$ meter movement per frame is too much for a usual camera.
Now either hook something to that vertex, or create another geonodes setup that uses the simulated data. Of course you could directly display the simulated mesh, but I went for separating the simulation logic and the appearance, so a simple sphere will be centered on that simulated vertex:

Now you can set the animation to last a very long time (99999 frames), run the script, and modify the simulation parameters as you go:

Rendering
Here's another example, this time making it possible to render, though it crashed for me after 500 frames. Maybe it has something to do with this note. To render, open the file, run the script, and then render the animation.
  tested on v3.4β

I like this approach! Just an idea for the list of most wanted nodes: "Bake to Cache" (output node, write to file/memory). Instead of outputting the geometry at the group output, the data of each frame is written to a cache, and can be read by other geometry nodes per frame with "Read from Cache" (input node). Would something like this be theoritically realizable as a custom node?

Geonodes are CPU based so EVERYTHING could be realizable… I wish rather than going for everything nodes, Blender would go for everything WASM (webassembly) which is a safe programming interface allowing to safely import third party code. Even within the node context it seems being able to write a custom node would explode the practical possibilities.

Here's a tweet and a gumroad page for a 9 months old solution, very similar to mine.


text:
Adding extra parts to a model
How can i add this part onto my mesh without adding a separate part.

Extrude it? That row of faces fits perfectly as a starting point.

Hello :). Please add some details about what you tried so far and where exactly you're stuck.

Also, maybe a little more info about why you don't want to add a separate part.

I decided to make it a separate part thanks for the help

As Nascent Space says, you can extrude that part, then flatten it on the Y axis:

I know that but when I shade smooth it and more verts it doesn’t look right. I also need the inside of that part to be empty

so maybe show what you've done so far so that we see the precise problem you're struggling with, or even share your file (the one with your extrusion attempt and fail)

Could always mark the edges sharp to fix the normals.

Will keep in mind to try sharp edges next time Thankyou so much


text:
How to prevent repeating textures on floor tiles array?
Basically, I wanted to create marble tiles with the array modifier and a texture I downloaded.
But I'm not quite sure how to make it look like it isn't just repeating. I'd like some randomness to it but I'm not sure how to achieve it. Could anyone help with this?

Since Blender 2.8, you've been able to set a U and V offset per element in an array. Well,OK, that's an offset. But it gives you access to more.
The elements' UVs change at the same rate as the Generated UVs of the whole array.  So if you have set any  UV offsets in your Array modifiers, and then take the difference between the element UV and the array's Generated UV, you get a per-element UV: a pair of numbers which is constant per element, but different for each, which you can use for anything you like. (Shown as color in the array on the left, below.)

In this example, the per-tile UV has been used to look up a color from a Noise texture. The  R and G found in the noise at that coordinate have been used to displace the Y location and Z rotation of an image texture, per tile.

Robin Bestt strikes again!


text:
Morphing a tiled diamond pattern around organic objects
I'm a complete beginner trying to replicate this "Cocoon" object.
I tried to make the tiled pattern by using several rotated cubes (to create a diamond) joined together by using array modifier and then creating the tiled effect by simply duplicating the first set of cubes and alternating them in such a way that the succeeding level of the set of cubes is lower than the previous set.
I wanted to morph the pattern onto an object using the shrinkwrap modifier. However, I've had no success in doing so.
I tried to shrinkwrap the pattern onto a cylinder, and fortunately, it worked.
However, on natural objects it just ends up deforming the pattern altogether, diminishing the "tiled" effect in the end.
Ideally, I'd like the pattern to be able to morph to any object without it deforming.
Is there any other way to do this?
A "Cocoon" at Baku Airport, Azerbaijan

Ctrl3 Subdivide the default cube

CtrlA on the subdivision modifier to apply it

go to Edit Mode, F3 Checker Deselect

CtrlB, V bevel vertices, drag

If you assign every other vertex (selection after Checker Deselect) to a group, you can use modifiers:

Weld is needed for smooth shading, but it defeats the purpose...


text:
Generating Realistic Reticulated Foam Material
Any tips for creating a realistic reticulated foam material or can somebody point me in the right direction of any tutorials. Thanks!

Related https://blender.stackexchange.com/questions/43596/how-to-create-porous-material/43780#43780

or https://blender.stackexchange.com/questions/124126/auxetic-foam-cell-structure/124298#124298


text:
Geometry nodes: multiple selection criteria
Problem statement
I have a simple node setup where I place some objects (grass collection) on a mesh if the z normal value is above 0.9.  I would like this to follow a noise pattern (like the voronoi) such that it clusters together in some parts and to be completely absent in others.
I've tried using the Poisson disk option and control the density frac with the output of the noise node. This doesn't work and I don't understand why. The output from the noise is between 0 and 1 and the input to density is between 0 and 1. Is it taking the average instead of calculating it per point?
What are the alternatives for having multiple conditions for selecting points?
Thanks!
Edit
Thank you Chris for providing the exact setup I was looking for. I didn't think about using the color ramp.
Also, Gorgious pointed out a very good problem! I was indeed only using a plane mesh and forgot about adding subdivisions.
Thank you very much for your help!

You base mesh needs to be subdivided enough because the density values are sampled at each vertex and interpolated on the polygon surfaces. Could you add a screenshot of your instancer mesh in wireframe mode ?

please provide blend file (best) or at least your node tree so we can effectively help you...

"normally" you would multiply if you have two logical and-conditions for your selection. Because selection just takes 0 (don't take into account) or 1 (take into account). For two logical or-conditions you can just take max(a,b)

You can use this node setup (but i am only guessing what you want and what you want to achieve...)

result:

result when you change the threshold for z-value:

Thank you! That's exactly what I was looking for!


text:
Gradient colour on UV mapping
I watched a youtube tutorial on making a clover and I want to make the same by myself. From the video, it seems that clover is shaded using UV map

and then some gradient texture in the "Texture Properties" tab instead of shading nodes.

The result is

However, I encountered some problems below:
1) The video is too fast to follow even though it is played at 0.25 speed
2) I am using Blender 2.82 but it seems that the Blender version in the tutorial is 2.79 or earlier.
Can somebody teach me how it can be done in Blender 2.8. Thanks a lot!

I guess it's this kind of node chain: Texture Coordinate > Mapping > Gradient > ColorRamp > Diffuse > Output.

Thank you moonboots. I get a very close image! Thanks a lot!


text:
How to drive object's local transform by another object, while relative to third object?
That title is probably a bit confusing so lemme try to explain what I mean:
Let's say I have two objects: Object A and Object B, and two cameras: Camera A and Camera B.
I want the position and rotation of Camera B relative to Object B to be the same as the position and rotation of Camera A relative to Object A.
Here's a visual representation of what I'm trying to do, with the two objects and cameras:

I've tried experimenting with different combinations of drivers and constraints, but I wasn't able to get it to work. If anyone could help me out it would be greatly appreciated!

There is probably a way to do this with constraints. In particular, the transformation constraint, which will let you map, say, the x axis of one object to the z axis of another object.

let me get it more clearly, suppose you drag one cam to the Right angle, do you want the other to appear in that same location but at the other arm?

@Neail I guess so yeah.

then you need a 3rd object constain cameras to that. disable that 3rd object in render.

You can do this with drivers and parenting.

Use Rightclick > Copy New Driver and then RMB > Paste Driver
Drive all location and rotation fields from Camera A to Camera B  (so they match perfectly)
Select Camera B and go Object Properties > Relations > Parent and target Object B

2. RMB > Copy Driver > Paste Driver from Camera A to Camera B. Do this for each location/rotation field.

3. In Object Properties of Camera B, target Object B.
Camera B will now inherit Object B rotation/location, but will also keep the driven position and rotation on top of that.

It works perfectly, thank you!

Great, I was a bit worried I didn't explain it well enough :). Good luck with your project.


text:
ArchViz Glass for quick renders in Cycles?

I have seen a number of different opinions on what light paths should be sent to the mix shader for doing archviz glass for quick renders. I've always used either just the shadow ray, or the shadow ray and the reflection. Some suggest using a combination of shadow, diffuse and glossy and I've even seen some including more beyond that.
What is the correct way and more equally important, why?
I'm putting together a general tutorial on Glass and I really want to ensure I'm giving out the optimal method here to the viewers.

Hello, are you planning to use Eevee or Cycles (or both) ?

Hey :). Also, are you looking for the physically correct way or 'archviz glass for quick renders' you mentioned?

Thanks for replying, Cycles is the target here and I'd say the focus is archviz glass for quick renders but I'd want to note what is being given up for the sake of speed too.

Note: This has nothing to do with physically based glass.

Andrew Price reccomends this 'Glass Hack shader' specifically for archviz renders, where caustics aren't that important. Relevant part of video here
Working principle
It doesn't affect Shadow, Diffuse and Glossy rays in any way, but your camera still sees a reflection when looking at it.
Pros: Very fast, low noise
Cons: No refraction

Hey, thanks for responding.
It's actually Andrew that I'm working on with this, I'm putting together a video for Poliigon on Glass and this setup may be the one I go with however not only do you lose the refraction but the reflections become unrealistically more pronounced.

Oh, that I didn't expect... :). Well, then this might be a bit out of my league...


text:
Rendering an animation only returns blank images
I am having trouble rendering my animation
When I click Render animation it will give me 40 blank images. The frames are all correct. I think I messed around with the settings too much.
I am quite new to blender, also I'm  using blender 2.79. Here's the file.

is this in video editing preset?

no, I dont think it is.

have you changed the audio settings or it is set to no audio

I didn't mess around with the audio settings so no

have you done anything in the video sequencer?

Try removing a strip from the Video Editor.


text:
How can I have a custom projection matrix?
I want to use a different style of projection, to achieve this effect:
effect http://www.boacompra.com/uoljogos/images/screenshot/tibia/shot10.jpg
I know how to create a projection matrix for it, but I don't know how to set that matrix on blender. How is it possible?

It is similar, but the projection is not the same and the answer there is very incomplete (he just tells Most raster graphics editors have the tools to preform the above transformations. This can also be done in the compositor using a Blend texture and the Displace node. without going any further).

Could you use some specific terminology for the kind of projection you're looking for? - such terms can be searched for, where images cant.

@ideasman42 I don't know any term for that projection, unfortunately. We call it "45 degrees", but it is an internal name. I'll update the post with the formulas, as you asked.

short answer is no, you cant set a custom projection matrix, however added an answer to the question this is marked as a duplicate of, which I think may help you.

I can't comment there, so thanks for the answer, @ideasman42 . Another suggestion people gave on #blender was to use a lattice instead. I found that very elegant.

Orthographic Camera Lens
In Blender, there are many settings that influence the way the camera views the scene, and hence how the scene is rendered. You can see these settings by selecting the camera in your scene, then looking in the Object Properties windnow:

Blender has three different Lenses cameras can use: Perspective, Orthographic, and Panoramic. The effect you are looking to achieve is called Orthographic projection/view.
To change a selected camera's Lens, do this:

Select the camera
In the Object Properties window, click on the Camera tab:

In this window, go to the Lens section and there you can select the Orthographic Lens:

Next, adjust the Orthographic Scale setting so your camera view includes everything you want it to:

NOTE: In order to keep the current view in Camera view when you adjust the camera's view, make sure you have Lock Camera To View enabled properly: when Lock Camera to View is enabled, the view will stay in Camera view when you pan or rotate the view. Otherwise, when you rotate the view, Blender will leave Camera view and go back into User view. To enable Lock Camera to View:

Properties panel (N) -> View section -> enable Lock Camera to View

You can read more about the different Camera settings in the Blender Manual here.

Unfortunately this is not Blender's Orthographic View. As you can see, the X/Y axis on my desired projection are not transformed at all. The formula is project(x,y,z) = vec2(x-z/2, y+z/2). Notice the tiles on the floor, the top of the piano, etc. It is completely different than Blender's orthographic view.

Oh, I finally see what you're trying to achieve. I would suggest you include your formula in your question, and also perhaps explain what the formula means, i.e. something to the effect that the X/Y axis is viewed from a Top Ortho view, while the Z axis is skewed. I think that would help other readers quickly understand the projection you want and there are lots of programmers here that might be able to figure out how to create such an effect. I don't think blender has built-in capability for that style of projection.

IdeasMan42 is very knowledgeable in these kinds of things.


text:
How to programmatically load a python script in Text Editor and launch it
With python API, is it possible to load a (new) python script in the Text Editor and then launch it (to automate things !) ?
I try this but it doesn't work :
bpy.ops.text.open(filepath="my-script.py")
bpy.ops.text.run_script()

Script name added in the text list but not visible in the Editor.

Where are you running this from?

From command line : $ blender.exe --python script-to-automate-things.py

My configuration : Blender version 2.69, OS Cygwin on Windows7

I must add that i just try to simplify the task for my project. Everything loaded and executed and the script ready to be completed in the text editor.

Every Text Editor has its own active (visible) text datablock stored in .text.
To call the text.run_script() operator, use a context override and give it the right 'edit_text' member.
import bpy

text = bpy.data.texts.load(path_to_file)

for area in bpy.context.screen.areas:
    if area.type == 'TEXT_EDITOR':
        area.spaces[0].text = text # make loaded text file visible

        ctx = bpy.context.copy()
        ctx['edit_text'] = text # specify the text datablock to execute
        ctx['area'] = area # not actually needed...
        ctx['region'] = area.regions[-1] # ... just be nice

        bpy.ops.text.run_script(ctx)
        break

Just a sidenote: You can also use area.spaces.active.text = text since area.spaces[0] is the active space.

It seems it can be done in less code even, just the following code, no TextEditor windows open.
# text = bpy.data.texts.load(path_to_file)   # if from disk
text = bpy.data.texts['some_file_name.py']   # if exists in blend
ctx = bpy.context.copy()
ctx['edit_text'] = text
bpy.ops.text.run_script(ctx)

executed fine!

Another technique is illustrated at http://web.purplefrog.com/~thoth/blender/python-cookbook/exec-text-library.html
import bpy
bufferName = 'lib 1'
lib1 = bpy.data.texts[bufferName].as_string()
exec(lib1)

this even works when the script being exec'd is importing local datablock .py files as modules. nice.

this can fail if the file you are trying to exec has a few imports not already present in globals/locals -- and this isn't being executed directly from the TextEditor.

You don't necessary need to load it. You can use a browser to get the path p
and then run exec(compile(open(p).read(), p, 'exec')). The script will be executed.


text:
Geometry nodes 3.0 random array stack
I am trying to create a random stack of meshes from a collection in geometry nodes.
Already I have an array that can detect the height of the first object but not on different objects with different heights. Is it possible to get the max height of every object and then stack them accordingly?
here is my blend file:
https://we.tl/t-unOsDy2LP2
Here is an image of what I have:

please paste pictures directly in your question. And instead of the node tree...please provide blend file. thanks.

Ah i didn't know i could do that. :) thanks. I will add the blend file as well.

This gets quite close (only for a collection of two, but if this could be made to work should be easy to expand to more): https://i.sstatic.net/c7Xel.png. The thing that's missing is a "cumulative sum" for the offsets, so that the next instance knows which ones got randomly selected before it..

UPDATE
With the new accumulate field node, you can use this node setup:

result:

My solution isn't for sure the best and it should be a lot easier with animation nodes (which has loops) but you wanted a solution in geometry nodes. So i made a nodegroup, which basically adds one vertex to the geometry, calculates its own height with the bounding box node and outputs its next starting point. But i am sure some geniuses here will present a better solution ;) but i hope you can learn a bit from my setup.
Here is the node tree:

result:

Thanks a lot Chris, this helps a bunch. Maibe there is a way to generate node groups to extend the array.

I'm trying to adapt this solution and think I'm getting close. Instead of outputting the distance to use as an offset for the next node in a chain, using that distance with a Sample Curve node to instance everything on a single curve. I've got it working with a single object input (based on its bounding box). The trick I'm stuck on is getting the distinct bounding boxes for each object in the collection (I'm starting to feel that part isn't possible yet)

I also have a feeling that it can't be done jet. I did make it work in unreal engine blueprints with forloops but blender works a bit differt in that regard i guess. Maibe it was possible with attributes form 2.9. I think Chris's solution is quite ingenious in joining the stack geometry and adding another instance and then joining agian.

Wow thanks for the update, this is very helpful.

I tried to figure out how to make it work with a collection of objects and accumulate the bounding box Z dimensions but it doesnt work. Any ideas? @Chris

Thanks, this is what i wanted to do.
I managed to do it with a sequence of your nodegroups and a couple of switches and a multigate.
Also I made seperate collections for the top, bottom and middle elements of the stacks.
basically you can put up to 8 middle instances into this system now and it will detect the heights. You could now collapse all middle nodes into another nodegroup and generate more instances exponentially.
Thanks a lot for your help.


text:
Accumulate field with a collection
Does anyone know how to make this works with a collection.
I tries implementing a bounding box node and accumulate the max z dimensions but i cant make it work. This screenshot came from Chris in reaction to another question

Edit:
This was my solution but it doesnt work.

There's some other thread here with a few answers, it's not something that works out of the box yet, looks like 'Bounding Box' doesn't do fields or something... here's a blend with my hackish solution, but there's something alike in there too.

@alambre: why do you think it is hackish? i would write that as an answer! Great job!

thanks..! maybe they all are? bounding box should work in this cases

@alambre had the answer here. Thanks this works.
Edit:
linking to Robin Betts solution ;)

nice but don't credit me, that is the 'Capturing Dimensions on Instances' setup that Robin Betts uploaded in that thread... I did almost the same thing though


text:
Is it possible to generate a vertex group using geometry nodes?
I have a mesh completely generated using geometry nodes.
I want to assign the vertices procedurally to a vertex group and use it in the armature deform modifier. Is it possible?
I tried to use named attributes but it doesn't work with the armature.

EDIT: My goal is to generate complex meshes with vertices, UV mapping, and armature deformation using only geometry nodes.

I think the answer is no. May I recommend to read these posts : get Vertex Group to survive Geometry Nodes and Transfer (float) vertex-attribute to vertex-weight, to allow GeoNodes to control subsequent Armature binding ?

Hello, user111.. Nothing personal, but this does look as if it's very probably a duplicate question. I hope the links provided in the comments, here, give you the answer you're looking for. If they don't, go ahead and edit your question explaining why not, and we'll be happy to re-open it.

Hi @RobinBetts, I have already read that solution. While it does fix the problem, it is a workaround that cannot always be used.

At this point, I think adding, removing, and editing vertex groups is not yet possible using geometry nodes.

Hello. @aarcangeli, I've re-opened in response to your edit. As I think you have concluded yourself (?) .. I'm afraid  it is unlikely there can be an answer that's an improvement on those linked here at this stage in Blender's evolution.  (As a personal opinion, I believe, in the long run, there should be no need for the separate category: 'Vertex Group', and that all modifiers, including  'Armature', will act on integrated Attributes. ... but hat's a long haul.) If your question is turning out to be fruitless, in the light of the other answers, it may be better closed. Let us know.

I found a workaround that works for me.
I wrote a Python script that generates a new mesh object "SK_Cubes" by copying the final transformed mesh from the object "Cube" and individually applying the attributes.
The first time the operation is executed, it will create a copy of the selected object with the prefix "SK_". If the object has already been created it will simply update it.
The cloned object may have the armature modifier.
import bpy
import bmesh
from bpy.types import (
    Panel,
    PropertyGroup,
)
from bpy.props import (
    PointerProperty,
    StringProperty,
)

def create_object(src, name):
    """ Create a new mesh object with the specified name, and link to the same collections of src object """

    mesh = bpy.data.meshes.new(f"{name}_mesh")
    obj = bpy.data.objects.new(name, mesh)
    obj.location = src.location
    obj.rotation_euler = src.rotation_euler
    obj.scale = src.scale

    for col in src.users_collection:
        col.objects.link(obj)

    return obj

def find_or_create_object(src):
    object_prefix = bpy.context.scene.vgutils_props.object_prefix
    target_name = f"{object_prefix}{src.name}"
    if target_name in bpy.data.objects:
        return bpy.data.objects[target_name]
    else:
        return create_object(src, target_name)

def transfer_evaluated_mesh(src, dest):
    print(f"Transfer mesh from {src.name} to {dest.name}")
    group_prefix = bpy.context.scene.vgutils_props.group_prefix

    # Generate a bmesh from the final transformed mesh
    bm = bmesh.new()
    bm.from_object(src, bpy.context.evaluated_depsgraph_get())
    bm.verts.ensure_lookup_table()

    bm.to_mesh(dest.data)

    # All attribute that starts with "b_" are converted to vertex group in the new mesh
    for attr_name, group in bm.verts.layers.float.items():
        if not attr_name.startswith(group_prefix):
            continue

        group_name = attr_name[len(group_prefix):]

        print(f"  - Copy group {attr_name} to {group_name}")
        if group_name not in dest.vertex_groups:
            target_group = dest.vertex_groups.new(name=group_name)
        else:
            target_group = dest.vertex_groups[group_name]

        for v in bm.verts:
            value = v[group]
            if value > 0:
                target_group.add((v.index,), value, 'REPLACE')
            else:
                target_group.remove((v.index,))

    # Remove all the groups with the "b_" prefix
    bm = bmesh.new()
    bm.from_mesh(dest.data)
    found = True
    while found:
        found = False
        for attr_name, group in list(bm.verts.layers.float.items()):
            if attr_name.startswith(group_prefix):
                bm.verts.layers.float.remove(group)
                found = True
                break
    bm.to_mesh(dest.data)

    print("  + Done!")

# Properties
class VGUtils_Props(PropertyGroup):
    """ Properties for the AutoMirror addon """

    object_prefix: StringProperty(
        name="Object Prefix",
        default="SK_",
    )

    group_prefix: StringProperty(
        name="Group Prefix",
        default="b_",
    )

class VGUtils(bpy.types.Operator):
    bl_idname = "object.vgutils"
    bl_label = "Bake Vertex Groups"
    bl_options = {'REGISTER', 'UNDO'}

    @classmethod
    def poll(cls, context):
        return all(o.type == "MESH" for o in context.selected_objects)

    def execute(self, context):
        print()
        print("=== Bake Vertex Groups ===")

        object_prefix = bpy.context.scene.vgutils_props.object_prefix
        for obj in bpy.context.selected_objects:
            if obj.type != "MESH":
                continue

            # Find the source and target objects
            if obj.name.startswith(object_prefix):
                src_name = obj.name[len(object_prefix):]
                if src_name not in bpy.data.objects:
                    raise ValueError(f"Source object {src_name} not found")
                src = bpy.data.objects[src_name]
                dest = obj
            else:
                src = obj
                dest = find_or_create_object(obj)

            transfer_evaluated_mesh(src, dest)

        return {'FINISHED'}

class VIEW3D_PT_VGUtils(Panel):
    """ Shows a panel in the "Edit" tab of the 3D View """

    bl_label = "Vertex Group Utils"
    bl_idname = "VIEW3D_PT_VGUtils"
    bl_category = 'Edit'
    bl_space_type = 'VIEW_3D'
    bl_region_type = 'UI'
    bl_options = set()

    @classmethod
    def poll(cls, context):
        return all(o.type == "MESH" for o in context.selected_objects)

    def draw(self, context):
        layout = self.layout
        layout.column(align=True)

        row = layout.row()
        row.operator("object.vgutils")

        vgutils_props = context.scene.vgutils_props
        layout.prop(vgutils_props, "object_prefix")
        layout.prop(vgutils_props, "group_prefix")

def register():
    bpy.utils.register_class(VGUtils)
    bpy.utils.register_class(VIEW3D_PT_VGUtils)
    bpy.utils.register_class(VGUtils_Props)
    bpy.types.Scene.vgutils_props = PointerProperty(type=VGUtils_Props)

def unregister():
    bpy.utils.unregister_class(VGUtils)
    bpy.utils.unregister_class(VIEW3D_PT_VGUtils)
    bpy.utils.unregister_class(VGUtils_Props)

if __name__ == "__main__":
    register()

PROS:

it works.

CONS:

it requires a manual action.
it retains a copy of the mesh in the blend file, making it larger.

EDIT: I thought you meant control a vertex group. If you mean create/name them via geometry nodes. Then unfortunately no :/
Yes you can actually. The vertex group just needs to be the same name as the attribute.

If we go into weight paint mode we can see our weights are indeed there

If we set that group in our armature

We can see they are properly deformed by our armature

Unfortunately, this method only works if the geometry is not procedural. If you cut the link with the input group and replace it with a procedural node like "Cube" you will notice that the vertex group is deleted.

I am using solution from https://blenderartists.org/t/can-geometry-nodes-output-a-vertex-group-other-next-modifier-could-see-and-use/1484924
cant post link on comments rep too low

from
Edit. i tested this and seems can only change one single named vertex group. if add another you loose first.

btw it's not a cheat or hack and if initial geometry has no vertices then needed only "Mesh Boolean" + "Store named attribute" nodes


text:
Lighting up a letter from one end to the other - Like a 3D "progress bar"
I would like to animate a 3D letter gradually filling with light from one end (kind of like a 3D "progress bar" that goes around corners).
I would also ike to ensure that the light has a rounded tip as it travels around the letter.
I have used a curve to create the letter "U" for the below example, and I have made a mock up of how I would like the light to progress around the letter (it's just using multiple static meshes, and is not animated in any way).
I would like to ask for some ideas on ways to animate the light smoothly progressing around the curve. I have limited experience with using curves in projects.
Any ideas are appreciated and thankyou in advance!

https://blender.stackexchange.com/questions/268252/round-smooth-the-end-points-of-curve-in-geometry-nodes

Does this answer your question? Round / smooth the end points of curve in geometry nodes

Thankyou Chris and Duarte, this might be helpful for rounding the edges, indeed! I still have the issue of figuring out how to animate light actually following the curve and filling the letter.

Geometry nodes might help. Look into animating a Curve Trim node

This one might help you with that


text:
Cant not Limit IK Bone Rotation of bone
I Need help with the rig
The image is when i using the boneIK to control finger ,The thumb2 work alright,but the thumb1 rotation out of where it should . Does IK limit rotation just work when theres connected parent?
*on the right is thumb1.r bone properties show the blue circle it should rotate *
Here's the File
Thank you!

could you please specify which bone you mean, what the result is and what result you expect? thank you

IK angle limits are not respected on the first bone of IK chains with pole targets.  You have to choose between letting angle limits control the first bone, or letting the pole target control the first bone.
Generally speaking, the less ways that you complicate IK, with angle limits and pole targets and such, the better those IK chains are going to function.  Many uses of angle limits are going to end up creating IK twitch whenever they come into play.
Most of my own IK chains do not have pole targets.  Thumbs are one where I typically do use pole targets, on a 3-bone chain.  But angle limits are not necessary on them; the initial metacarpal is the only bone that rotates in more angles than a simple hinge.  Control of the initial bone can be tuned by IK stiffness and by placing the IK target and pole in reasonable positions.