text:
Does gltf only support the export of one strip per NLA track?
This blend file contains only the default cube. I've create two Actions:
MyTrans that implements only a translation &
MyRot that implements only a rotation.
Each of those Actions, I've 'pushed down' to create an NLA strip on NLA tracks called MyTranT and MyRotT.

So far, so good. If I export the cube to a gltf 2.0 file, and then load the exported file in a viewer, I can see the two tracks, identified by trackname  & play either one, or both at once.
The problem occurs when I restructure what's in the NLA editor a bit. Here, I've added a copy of the rotation action to the MyTranT track.

I can play either track within the Blender IDE. In particular, playing the MyTranT track results in a translation followed by a rotation.
However, if I now export as gltf, only the single action track seems to get exported.
I'm using 2 online gltf viewers:
https://gltf-viewer.donmccurdy.com/
https://sandbox.babylonjs.com/
both behave the same way in this regard.
Both actions have users, MyTrans has 2 and MyRot has 3. Neither action is lost when the blend file is closed & reopened. I've also tried giving each action a fake user.

makes no difference though, the track containing 2 actions doesn't seem to get exported.
For both these situations, I've tried exporting as glTF Embedded and examining the text output.
In the first situation, where there is only a single action in each NLA track, the only names visible in the text output are those of the tracks, ie MyTranT and MyRotT. The action names appear nowhere.
In the second situation, where one track contains 2 actions, it's a bit mixed up. For the track containing a single action, ie MyRotT containing action MyRot, the name 'MyRot' is visible in the output. For the track containing 2 actions, ie MyTranT, the name of the first action on that track, ie 'MyTrans' is visible in the output but the track name is not.
So my question is, why doesn't this work?
Blender 2.83.3 on Linux

The exporter can only use a single strip per NLA track, yes — the limitation is tracked in https://github.com/KhronosGroup/glTF-Blender-IO/issues/763.

Not sure how to indicate here that a comment has answered my question.

Sure, I've added an answer.

The exporter can only use a single strip per NLA track — the limitation is tracked in github.com/KhronosGroup/glTF-Blender-IO/issues/763.

I think you need to mark every action as "need to be exported". Lets try to be clearer.
In Blender, an action (or a material, or whatever) that is not assigned to something is considered as lost instead you specify otherwise. You can specify you want to keep it by clicking that Shield icon :

If you don't do that, that datablock won't be saved with your blend file ; and sometime, won't be exported (well, that depends of the exporter script).
If you don't want to struggle with a glTF viewer and just want to check if the data is indeed included in the file, you can export in "glTF Embended" and just check it with a text editor ! Simply search the name of your action and see if it appears in the file. The file structure is JSon so it's (more or less) human readable.

Thanks but this makes no difference. I've edited the question accordingly.


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How to limit rotation on the last bone of an ik chain
The last bone here, Bone7, has an ik constraint of chain length 3. As in the image, moving ikBone moves the bones all the way back to bone4. This makes me think that the length of a chain doesn't include the first bone, Bone7. Or that the counting starts at zero.
I want to limit the rotation of Bone4, the last bone in that chain.

I think that ik overrides Limit Rotation bone constraints and the way to achieve the result I want is via the Inverse Kinematics tab, found in the bone properties as described here
Those constraints work ok for Bone6 & Bone5, the 1st & 2nd bones in the chain. Here are the constraint fields for bone 5.

The problem comes with Bone4, the final bone in the chain. Looking at that same constraint panel for Bone4, the fields are greyed out.

Although greyed, values can be entered in the fields and the check boxes can still be checked. Setting up various test situations, for reasons unknown to me, sometimes the Bone4 ik constraints are enforced and othertimes not.
So my question is, what is the significance of the fields being greyed and in what circumstances are those constraints enforced?
Blender v2.83.0 on Linux

The Chain Length of the Inverse Kinematics constraint is including the bone that has that constraint. In your case the value is 3, so it applies to Bone7, Bone6 and Bone5. Therefor Bone4 is not part of the the IK setup and it's rotation behavior cannot be limited by the Inverse Kinematics settings in the Bone Properties.
You can increase the value of the Chain Length to include Bone4. (Or put a Limit Rotation bone constraint on it in the Bone Constraint Properties tab if you don't want it to be part of the chain.)
Also when Relationship Lines are active (which can be made visible by checking the box in the Overlays menu), you can see a line from the start to the end of the chain that can help determine the length in the 3D Viewport.
Edit:
Note that if the box next to Use Tail is not checked, the bone that has the Inverse Kinematics constraint, is not part of the chain. However in this case that bone (otherwise first in the chain) is not affected by inverse kinematics, and (more importantly) the last bone in the chain cannot be constrained in the Bone Properties > Inverse Kinematics menu.

If that's the case, why is my first image showing a chain of length=3 reaching all the way to bone 4? bone4 should remain unchanged, just like bones 1,2 & 3. I've edited the question a bit to explain why I thought that.

Ah, i see now. I didn't realize you didn't have the Use Tail box checked. I edited my answer accordingly, and advice to have that box checked. It seems to me that not being able to constrain rotation of the last bone in the chain when it is checked, is an oversight. To be honest, at the moment I can't think of any reason why it can't or shouldn't be possible to constrain if Use Tail is not checked (but apparently it is). In any case; hope that helps.

yep, increase the chain length to 4 & check 'use tail' and it works as expected. thanks

source: Stack Exchange

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Is it possible to backlight an image plane?
I have a footage of somebody walking towards the exit of a tunnel. I want him to walk into the bright light of the exit, so that he dissolves in the light.
Since I didn't have a strong big light to light the exit, I wanted to make it in post.
Is there also a possibility in Blender to set a spotlight behind the image plane, so that the spotlight shines through the back of the image plane respectively the video footage?

Can you check if this answers your question?

You can disable shadows in object properties → Visibility → Ray Visibility:

Thanks a lot Crantisz, I will try it today!

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Subdivision not working as expected
I have subdivided my mesh and in two spots it seems to be sticking to the original vertices:

I tried deleting the surfaces surrounding that area and remaking them with no success. How can I make this issue go away?

Check if you have any overlapping vertices. If you look at the 2 other shapes, they are okay.
Select All with A, then press M and merge by distance.
Alternatively you may have some "Edge Crease" on edges. So enable Overlay to check for that.

You can also check the exact value of a crease in your geometry on the side panel.
Select edge and check creasing for both vertices and edges:

Thank you. It did, indeed, seem to be solved by merging vertices.

Thank you for all of your help. My apologies for not accepting the answer earlier. I am new to this StackExchange and after you brought it to my attention it took a while for me to find how to accept. Thanks again.


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Keeping true size on UV maps
I'm trying to unwrap my UV map to the correct size - it is in my layout page.
It may be a bit of an odd one what I'm trying to use Blender for.
We are trying to create visual layouts for customers where we can show them what the job will look like. We have a sized image of a marble slab and have sized templates (.dxf) which we have converted to mesh.
The sizes are both correct but when I unwrap them, they are not the correct size. I've tried Normal unwrap, Smart UV Project, Project from view, etc., but nothing seems to give me the correct size.

How should it give the correct size? A UV map has a normalized 2-dimensional coordinate system, it goes from (0, 0) in the bottom left corner to (1, 1) in the top right. And this is independent from any image size or image ratio. If you have a square image the top right will be (1, 1) and if the ratio is 16:9 the coordinates in the top right are still (1, 1). And using the automatic unwrapping methods will most likely result in Blender trying to match the UVs to fill the map, no matter if the object you unwrap is gigantic or tiny.

Cheers Gordon so will it not be possible to do it to the correct size do you think? cheers


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Why is my dark field photography setup for glass looking different from what a real studio setup would?
I am trying to replicate a dark field photography setup for glass. Similar to this:

The final goal is to get a set of clean reflections on a transparent background that I can composite with the separately rendered content for the glass later.
However I get all sorts of transmission and reflection artefacts, that do not appear in real photographs with similar light setups. Especially the middle segment, which is completely without reflections in the reference is bugging me out.
I tried to separate the gloss and transmission rays in the blender compositor, but without success.
I think it is a problem with my glass shader, but I am out of ideas what settings to tweak. The setup looks like this at the moment:

Any help is greatly appreciated!


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How do I use drivers to endlessly loop something spinning forward and in reverse back and forth?
I've created an animated scene that has a series of shapes that rotate endlessly using drivers. I do not want to key any animation.
I found a tutorial for a spinning portal on YouTube that uses the #frame command to spin an image of noise around on a flat plane. All the other shapes in the scene need to endlessly loop in the same direction. However, I need the spinning portal to switch direction so that, for half the animation it spins one way and for the other half of the animation loop it spins the opposite way.
If this helps at all, it has to do with the degrees of rotation and not the number of frames. For instance the one shape, an orb, rotates 360 degrees but also, so does the portal (rather the portal orbits). The difference though is that when the swirling portal reaches the 180 degree mark of its orbit, it then needs to reverse the direction the portal is swirling in.
Here is a link to the portal tutorial I used, Create an interdimensional Portal in 3D

Looping a rotation that goes back and forth is actually trivial, because you simply animate it to go forward, then back, and so it returns to its original state and the animation can repeat.
Assuming you don't want the rotation to suddenly switch directions and you want easing, so a sinusoide is perfect for that:

switching rotation direction thrice within 10 frames is definitely too sudden. Also the rotation should go from $0$ to $π$, or from $-π \over 2$ to $+π \over 2$ or you know otherwise $π$ range ($π$ rad $ = 180°$).
So as the sin() operates on radians and has a repeating period of range $-π..+π$, we want to:

Calculate the percentage of animation, for an animation going from frame #1 to frame #200 it's $x \over 200$, where $x$ is the frame number
multiply this percentage by the range sin expects, so by $τ = 2π$
the output of sin is $-1..+1$, so this time need to convert in the other way, either normalize and multiply by the desired range $π$, or multiply by half of the desired range (because half negative and half positive give you the whole range).

The driver: sin(frame*tau/200)*pi/2


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Tris to Quads using UV map
I have some old models that I need to repair. When I use Tris to Quads it doesn't work properly preserving the edgeloops because of the curvature of the models. But the UV map of the model is perfectly squared. Is there a quick way to remove the unwanted edges using the UV map? I can do that manually but it takes way too much time.

Can you provide that mesh to test on something?

@RayMairlot Sure, I will upload the file in a min

@RayMairlot I attached the blend file

The UV layout for this model makes selecting rows very easy with the Box Select tool.  (I hid the ends because they have hidden faces that are causing problems.)
By selecting every second loop of the UV's and then using Tris To Quads, you can establish guide loops that allow you to use the tool again and achieve consistent results.
b for Box-Select.  Also make sure to activate the icon for use_uv_select_sync as shown in the animation.

Now use Tris to Quads on the selected rows, then select everything and repeat Tris To Quads.

Now you can repair the few mistakes by using the Join tool j.  In the following case, I used Join and then used Make Face f to make a quad at the center of the error point.

I tried that before but it doesn't work well on surfaces that have lots of angle changes between the faces, the best I could do is to rotate the UV 45 degrees, select the every second diagonal edgeloop and dissolve , then invert selection and dissolve again, then rotate UV back.

There doesn't seem to be an easy way to convert the existing mesh to pure quads without quite a bit of manual intervention.
Here's an alternative way to create a new mesh with quads and keep a reasonable and even UV mapping.

Create a cylinder with no caps around the dress object
Copy the height of the dress to the cylinder so it is exactly the same height
Make sure the top and bottom of the cylinder match exactly the top and bottom of the dress Add subsurf mod and shrinkwrap mod (with dress as target) to cylinder Adjust subsurf as desired
Apply shrinkwrap modifier Select vertical edge loop at back of
dress, create seam UV unwrap cylinder object with cylinder projection type
Adjust UV map to fit UV image Trim vertices at top and bottom of cylinder

This may seem like a lot of steps, but it goes quite quickly. Let me know if this helps at at all

That will not work in my case, I have many of these meshes, some of them have 4-5 different baked textures, and the UVs have to match exactly to prevent distortion

Ah, I see. Didn't realize you already had pre-existing texture maps.

If you handle this part well, you can use the baking tool 'Selected To Active' to transfer the old textures to the new mesh.

This works for me:
import bpy
import bmesh

# go into edit mode
bpy.ops.object.mode_set(mode='EDIT')

# deselect everything
bpy.ops.mesh.select_all(action='DESELECT')

# Get the active mesh
obj = bpy.context.edit_object
me = obj.data

# force face select mode
bpy.context.tool_settings.mesh_select_mode = (False, True, False)

# Get a BMesh representation
bm = bmesh.from_edit_mesh(me)

count = 0
# find every second face and select the first edge
for face in bm.faces:
    if (count % 2) == 0:
        edge=face.edges[0]
        edge.select_set(True)
    count = count+1

# dissolve edges
bpy.ops.mesh.dissolve_edges(use_verts=False)

# deselect everything
bpy.ops.mesh.select_all(action='DESELECT')

# Show the updates in the viewport
bmesh.update_edit_mesh(me, True)

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


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Setting sun direction on sky texture with an empty
I am trying to control the direction of the sun on sky texture with an empty, I set the direction of the sun controllable by the rotation of the empty with drivers, each axis corresponding to the XYZ direction of the sun, but the result is not behaving as expected.

why not simply parent the sun to the empty?

@TARDISMaker The sun is not an object, it is generated by sky texture node.

Oh, okay, sorry. I didn't read your question carefully enough.

Define 'not behaving as expect'. You know the drill, what is it doing and what are you expecting?

The sun should be in the direction of the empty arrow, right now it looks like the axes of the empty are not corresponding to the sun direction and the rotation of the sun direction with the empty is not cyclical, so I assume that the sun direction coordinates are different, Im still not sure where is the problem.

The sun direction is defined as a normal direction, not sure how to convert euler rotations to a normal though :/ Related: http://blender.stackexchange.com/a/10577/599 and http://gamedev.stackexchange.com/q/82170/45856 (I've tried this before too :P)

@gandalf3 So as I expected the values of the rotation are from 0 to 1

@Denis AFAIK they are from -1 to 1

@gandalf3 yes using quaternians. In the related question you added the node setup doesn't work because when I change normal vector input it rotates the sky texture and not the direction of the sun separately.

@Denis Right, you have to control the sun direction with drivers. The normal input rotates the sky texture as you said.

Sun direction in the sky texture node uses values of normalized vector that can be taken directly from World Matrix.
X value - matrix_world[2][0]
Y value - matrix_world[2][1]
Z value - matrix_world[2][2]

My suggestion is to use  "single property" variable types, especially for nodes.  The x rotation driver would have a datapath of rotation_euler.x (or rotation_euler[0])

That wouldn't work because sun direction uses normalized vector, I already solved this problem and going to add the answer.

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


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How to project UVs from one object to another?
How to project UVs form the big object to the small one to display part of the image that is behind it as shown in the snapshot below.

Use object coordinates with the desired object as target?

@cegaton from what I see UV project modifier uses coordinates of the object only, if I move or rotate the mesh in edit mode it has no influence on the UVs of the small object.

maybe if you "Ctrl+A" apply rotation/location it will work?

I think the simplest way to do this is to join the two planes into a single mesh. Then position the viewport to be perfectly perpendicular to the planes, enter Edit mode and UV Unwrap from View. Then when you apply the image to the material using UV texture coordinates they will align perfectly. You can then separate the meshes and they will keep their UV layouts.

Update:
In order to accomodate the skew of the mesh, the uv layouts must be edited concurrently. Here's how to do that.

Join the two meshes. Unwrap with project from view.
In the UV editor select all and size to 90% of the uv grid area.
Turn on UVs>Constrain to Image Bounds, and Enable Proportional Editing in 2D mode.
With all vertices selected move the vertex group to the lower left corner. Then in turn, with a fairly large proportional range selected, pull each of the other 3 corners towards each corner of the uv area. If your proportional edit range is large enough, the edits to the large mesh will affect the small mesh.
Once done, leave Edit mode and check the alignment on the meshes. The two meshes can be separated at this point.

Update 2:
Denis shared his alternative which used the Shear command (CTRLSHIFTALTS) to tilt the vertices instead of using proportional edit. This was a great solution for this specific mesh issue.

I was thinking to do something like that in the beginning but the problem is that the mesh is not a square, the vertices have a slight offset, if I project from view the image will not cover the whole mesh.

You could probably still get away with project from view and then pinning the relevant vertices for the overlap and then unwrapping the rest with a different method. I'll look at the file.

That solution was good, but instead of using proportional editing I used CTRL+ALT+SHIFT to shear the UVs and cursor at 0,0 as Pivot Point to avoid distortion as much as possible.

That's a good alternative, I like that, have not used shear before. Maybe I should replace the prop editing answer with the shear one?

Here is more convenient way to do so:
You need UV mapped object as source and another object with the same texture but any mesh data with assigned UV map as target.
For target add DataTransfer modifier, select source object, enable Face Corner Data transfer as Nearest Face Interpolated and below click UVs as face corner data layers to transfer.

The result quality depends on target mesh density.

This is the correct answer. It doesn't rely on merging objects or manually editing the UV map, and always gives correct results, regardless of geometry.


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Object disintegrates into shadow and pieces when I change viewport?
im a noob trying out blender. All was going well until suddenly when I change the view port it disintegrates? I dont know how to describe it.
I was just changing viewports when that happened, how can I fix it?
To add: I dont have any textures or uv unrapping. Only some modeling, subdivision surface, smoothing and I applied a boolean before subdivision. Thats all

you must have pressed Alt B (Clipping Border), press Alt B again

@moonboots oh wow you're right. I was panicking for a moment, thanks a lot :)


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How can I control the exact transform value of bezier curve handles?
I want to make a perfect 90 degree bezier curve. How can I enter a value for the transform of the curve handles and control points?

You can enter numerical values for a selected control or handle using the sidebar.  If your curve tangents are aligned to an object's local axes, you would use the same X for a control and all its handles, and the same Y for the other control and all its handles, to create a 90 degree curve.  For an object not so aligned, you could create it while aligned and then rotate it, or you could use trigonometry to calculate exact-ish (limited to floating point precision) positions.

That answered my question, thanks.


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Why does my FBX model scale 100x when exporting to GLB?
I have a simple model in FBX, when I export it to a GLB file it comes out scaled 100x too big.
Is there a setting on export that I am missing?

did you apply your scale before?

I ended up having to apply a scale in blender after import to get the export to be correct scale.


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Toon Outline Not Following Armature
I've been building my own character mesh and following the Lightning Boy Studios videos on Youtube to try to create my own toon shader/outliner. For the outliner, I'm using a solidify modifier with a black emission material and backface culling enabled. Everything was going fine until I added a few armature bones just to do a preliminary check on how the mesh would behave under animation. When I moved the armature, the main mesh followed the armature, but the solidify outliner didn't follow at all (see reference image). I'm using automatic weights for the armature. My solidify modifier has already been applied. When I go into weight painting, I can't seem to be able to apply weight to the outline. I'm not sur how to fix this issue to allow the outline to move with the rest of the toon-shaded mesh. Can anybody help me solve this?
Thank you!

My guess would be that the Solidify modifier was before the Armature modifier on the stack. But you wrote that you have already applied the Solidify modifier. How many character meshes (objects) do you have? According to the screenshot, the base mesh is deformed by the armature but the outline not?

I thought the same about the modifier stack, but, like you, I figured it wouldn't be an issue if the modifier was already applied. The base mesh for the torso, arms, hands, legs, and feet are all one object. The head, eye, nose, hair, teeth, tongue and eyebrow are separate, but as you can see, the issue is present with a part of the mesh that is a single object. Yes, base mesh is deformed but the outline is not.

I'm inclined to think this is a glitch that is occurring due to my having applied the solidify modifier. I'm not sure how to fix this now besides rebuilding the entire mesh, though, which is very unfortunate.

can't you just delete the outline and add the solidify modifier again?

Tried that. If I add the solidify modifier again, it behaves like I want it to....but...it seems that when I applied the solidify modifier, it permanently created some mesh that is a part of the model. basically I get the result I want plus this extra mesh from the applied solidify modifier. I'm not sure how to get rid of those faces, as when I enter edit mode, the mesh I don't want snaps to the mesh I do want, and I can't figure out how to separate them other than with the armature (as pictured).

The armature modifier has 4 icons right next to its name. If you activate the On Cage and Edit Mode (the first 2 icons) then you can edit the deformed mesh. Also, it looks like it's loose mesh. You can select a vert and then press L to select all linked vertices automatically. Maybe this helps you to get rid of the unwanted mesh?

wow! that's a great idea. it worked well up until pressing L. I guess because the solidify modifier is applied, it views those verts as connected to the same mesh (which is super confusing since it's not behaving like the rest of the mesh in animation ???). I'm worried that if I proceed this way, it may take a while to move the mesh around to try to get all the verts deleted, and I'll inevitably miss some, too. wondering if this is the better approach or simply starting over since it's a relatively simple mesh to begin with. thanks for your help!!

Basically, if you're creating a toon-shaded character with the backface culling solidify modifier for an outliner....don't prematurely apply the solidify modifier to your mesh, or you could run into this issue too once you start animating. just leave the solidify modifier unapplied and make sure it's in the right place in your stack relative to your armature modifier, and you'll be much better off. Thanks for your help in talking through this, Blunder!


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Normals create black spaces in Cycles but work fine in other rendering engines
I am relatively new to blender and recently learned to bake normal maps. I did this and it worked fine (It looks great in Eevee) up until I switched to Cycles. Now, either the normal gets misaligned, or the whole thing turns black, or just parts of it turn black like the picture. Not sure why Eevee likes my normal but cycles doesn't. Any help would be awesome!

So, messed around a bit and I guess it randomly started working? Not sure why. I'd still love feedback about what may have caused this problem and how to fix it if it comes back :/

Normal map node strength too high?

you need a 32 Bit-Float image, maybe it's the problem? Maybe share your file? https://pasteall.org/blend/


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Export animation as a video for editing later
I have simple 10 sec animation and I want to render it into a video file for future video editing. I've used FFmpeg video format option in Blender with MPEG-4 container, H.264 codec and Lossless output quality, but generated mp4 cannot be opened in Quicktime (I use mac os), only in VLC. More importantly, I cannot open it in DaVinci Resolve (it is not recognised).
What is the best format to use, so that it won't noticeably worsen the quality and can be easily used for editing? Are AVI Raw or AVI JPEG good options?

AVI Raw is true lossles, but no audio support, if it is not crucial for you.

IMO the high quality setting of h264 does the job most of the time but for true lossless I often end up using a sequence of PNGs

For editing purposes, it's fairly common to use a sequence of images files, not a video file. Most editing software support them (DaVinci Resolve definitively do), and you don't have to struggle with codecs, bitrate or whatever.
In your output settings, just select a picture file format. Png is great if you have a transparent background. Lossless Jpeg is great if you've got a solid background.
There are other benefits with files sequences ; ie., you can pause the render between two frames and relaunch it later ; or render it with multiple computers (ie. a renderfarm).

Never thought about that, definitely going to try using sequence. I've also found out that perceptually lossless option produces viewable video. Then I can compare these options. And by lossless jpeg you mean Quality option set to 100%?

Yes that's what I meant

Overall a nice answer but... never ever render to png, recommend render to OpenEXR especially when dealing with alpha: https://blender.stackexchange.com/a/106671/31447

Thx, I never noticed issues with Png but I will try OpenEXR!


text:
Why does my photo not show up when importing it?
I've been following this tutorial on YouTube, but when I add the photo (around 0:40 in the video) the photo doesn't show up. Does anyone have an explanation or anyone have a better tutorial?

Hello! could you please provide some more information. Which type of image are you trying to use and which render engine? Maybe share your .blend file using https://blend-exchange.giantcowfilms.com/

Thank you for replying! So I am using a JPG to add as a background(?) I think and I'm using Eevee. This is the .blend file

Wait, I think i'm figuring it out

photorealism can not be achieved with eevee. Also there is no shadow catcher option in eevee, you would have to fake it: https://www.youtube.com/watch?v=DQJ_SBpcUQE

Related link: https://blender.stackexchange.com/questions/69832/realistic-rendering-of-mesh-together-with-image/69862#69862


text:
How come the Blender 2.83 Splash Screen by Ian Hubert takes so much less time to render than my Doughnut tutorial?
I'm completely new to blender and going through the Doughnut tutorial at the moment. I'm working on an old laptop (GTX 850M, i5-4210U, 8GB RAM) and the doughnut and cup together take about 10 mins to render.
So just for the fun of it I decided to download the Blender 2.83 Splash Screen by Ian Hubert and render
it on my machine, expecting it to render for something like a day. :P
But to my surprise, it took only 47 secs to render!
I realize that the splash screen is using Eevee and the doughnut tutorial uses Cycles but my mind was still completely blown by the time difference.
So my questions are:-

What are the most important factors contributing to the less time taken by the Splash screen? Or should we just chalk it up to Ian being an actual Blender god?!

More importantly as a beginner, should I spend more time and effort learning to use the Eevee renderer seeing that it takes much less time?
Or is it that the more experienced you become on Blender the difference between the two render engines becomes less pronounced and you can master both of them?

Hi. Please only ask one question at a time. You are welcome to ask multiple questions but as separate posts. I suggest editing your question down to just one question (by using the [edit] link below it). Normally I would suggest asking your other questions separately, but in this case your second question would be considered off-topic because it is opinion based. Thanks.

While Cycles is a "path tracer", Eevee is rasterizer.
"Unlike Cycles, Eevee is not a raytrace render engine. Instead of computing each ray of light, Eevee uses a process called rasterization. Rasterization estimates the way light interacts with objects and materials using numerous algorithms. While Eevee is designed to use PBR principles, it is not perfect and Cycles will always provide more physically accurate renders. Because Eevee uses rasterization it has a large set of limitations."
https://docs.blender.org/manual/en/latest/render/eevee/introduction.html
for example almost all game engines are Rasterizer. That way we can "fake" most stuff to look like the real deal.
And you are in luck. Eevee and Cycles are very close togther in node setup so your work is have been cut in half already. But what you do need to learn is the Eevee limitations.
https://docs.blender.org/manual/en/latest/render/eevee/limitations.html


text:
What do these orange lines in Object mode mean?
What do those lines mean? And why they are inconsistent?
I think my vertices need to be merged?

Hello :). Blender highlights geometry edges so they're easier to see in x-ray mode. Don't worry about it being discontinuous.

These are probably edges that are not part of any faces, for example if I extrude this vertex in Edit mode it creates an edge, here is what it gives in Object mode:

Run the 3d printing checks and fix whatever gets flagged.


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Why is only a small portion of my scene appearing in the render?
This is what I get when I hit render (I've now tried unselecting crop and boarder with the same result):

This is what I want to render:

This is the first time I've made something using blender however so I'm sure I'm making some basic mistake.
To be clear, in the pictures the rendered one is what I get whenever I hit render, the other picture is what I've "made" and am trying to get rendered to a PNG file but nothing I do or can find shows me how to get the whole image, and I keep getting the same small blurry square instead of the full scene pictured.
When I use camera view this is what I see which seems to be the source of the problem:

I am not understanding what you wan to do, if you want to render the entire earth with the shadow on the bottom. Hit "0" on the number pad to enter camera mode and just back the camera up until the earth is as big as you want it, Then re render.

Hitting 0 just made the earth disapear :/ and I rendered a black square. But yes idk what settings control what is being rendered seems like anything i change it still render's that small square instead of the scene i want.

For future questions please explain thoroughly what your problem is in the question body, your pictures don't "pretty much show the problem" and aren't very elucidating. Also post your images locally using the button in the toolbar.

well i don't know how to describe it, i tried writing a description in the pics to say what i wanted to achieve but i don't know much about the program sorry...

Have you setup a Camera object in your scene? Is the image on your viewport seen from Camera view?

I edited the post to show what camera mode is showing i was under the impression thats what i was viewing it through the whole time

I figured it out, i knew it was something i overlooked. As stupid as it sounds i only now realized what the camera actually was i'm sorry if i wasted your time but you helped me figure this out so thank you.

You have both Border and Crop active in render settings.
Turn off both border render and the crop option to get a full image.
You can also clear the render border by pressing Ctrl + Alt + B

Actually, as Ray Mairlot mentions the problem is that your camera is not well positioned, the earth is not fully framed, and what you see in the viewport is outside the view angle.
Just select your camera object and move it backwards, or increase the view angle from from the camera properties in the Properties Window > Object Data > Camera.

first, thank you for responding. Second, i unchecked both but was still met with same small square. Earlier while searching for an answer i came across a post that said to use CTRL B to draw a boarder and select those two options to get the part i wanted but it didn't work. :/

Ctrl+B Activates border render, Ctrl+Alt+B clears the border. To be clear both must be turned off. If that doesn't solve the problem then one would have to have a look at your scene settings or file

@DuarteFarrajotaRamos I think they literally just want to move the camera back so the whole of the earth is visible, like in their second picture.

@RayMairlot Oh, right. I see now, that image clears it up.

Yea i apologize, i didn't realize that shape was the camera the tutorial i watched showed me how to make the earth, but not much else, i really appropriate you all helping me to figure out a stupidly simple "problem" thanks anyways.


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Blender 3.0 (or above) texture baking problems
I'm having several bugs when trying to bake textures in Blender 3.0 (or any version above that) for quite some time. I thought something was broken in the alpha version, so I kept using Blender 2.93 for baking textures, but those problems persist on the recent stable version as well, so I think there is something wrong with my system or something has changed in the baking process, anyway I didn't find anything online about it.
For example, one of the issues is when baking combined textures, UV Seams end up being visible in the final baked image, even with a bleed margin properly set in the bake settings.
I made this simple file to demonstrate the issue, just a sphere with UV seams marked and UV unwrapped. As shown in the image below, in Blender 3.0 the UV seams are visible in the baked image while using the exact same file for baking in Blender 2.93 results in a proper clean baked image.
Has anyone experienced bugs while baking textures in Blender 3.0?
Could someone please try to open the .blend file below in Blender 3.0 and just simply press "bake" to see if the seams are visible in the baked image?
Thanks in advance!

Just got an answer in discord, turning off render denoising in render settings solves the issue. Don't we all like super simple solutions for stupidly annoying problems? yeah


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Blender keeps crashing at random. Problem with Action constraint?
My Blender keeps crashing at random intervals whenever I am in a project using two specific rigs I put together. Most of the time it's completely fine to use them, but other times it suddenly begins crashing again and again, and I can't find a pattern that causes this. My drivers are up to date.
My theory is that it is spamming the Action constraint for some reason, causing it to use too much memory and shutting down.
I do not know how to add a .txt file to this question, but here are some excerpts from the debug log:
WARN (bke.anim_sys): C:\Users\blender\git\blender-v340\blender.git\source\blender\blenkernel\intern\anim_sys.c:3541 animsys_calculate_nla: NLA Eval: Stopgap for active action on NLA Stack - no strips case
There's 3 of these, not sure if relevant.
Dependency cycle detected:
  OBRig Cano.001/TGT-JAW/BONE_CONSTRAINTS() depends on
  OBRig Cano.001/CTRL-MOUTH-CORNER.R/BONE_DONE() via 'Action'
  OBRig Cano.001/CTRL-MOUTH-CORNER.R/BONE_READY() via 'Ready -> Done'
  OBRig Cano.001/CTRL-MOUTH-CORNER.R/BONE_POSE_PARENT() via 'Pose -> Ready'
  OBRig Cano.001/MCH-INT-MOUTH-CORNER.R/BONE_DONE() via 'Parent Bone -> Child Bone'
  OBRig Cano.001/MCH-INT-MOUTH-CORNER.R/BONE_READY() via 'Ready -> Done'
  OBRig Cano.001/MCH-INT-MOUTH-CORNER.R/BONE_CONSTRAINTS() via 'Constraints -> Ready'
  OBRig Cano.001/MCH-MOUTH-CORNER.R/BONE_DONE() via 'Copy Transforms'
  OBRig Cano.001/MCH-MOUTH-CORNER.R/BONE_READY() via 'Ready -> Done'
  OBRig Cano.001/MCH-MOUTH-CORNER.R/BONE_POSE_PARENT() via 'Pose -> Ready'
  OBRig Cano.001/TGT-JAW/BONE_DONE() via 'Parent Bone -> Child Bone'
  OBRig Cano.001/TGT-JAW/BONE_READY() via 'Ready -> Done'
  OBRig Cano.001/TGT-JAW/BONE_CONSTRAINTS() via 'Constraints -> Ready'

This one is repeated once more, with the exact same thing written, followed by: Detected 2 dependency cycles
I see that there's a dependency cycle here, but it should be on all the rigs I made and it's only with these two the problems arrive. Then this keeps getting spammed, etc., etc. Most of the debug file is this:
do Action Constraint Action - Ob CameraShakify.v2_Camera.011_0 Pchan (null)
do Action Constraint Action - Ob CameraShakify.v2_Camera.012_0 Pchan (null)
do Action Constraint Action - Ob CameraShakify.v2_Camera.013_0 Pchan (null)
do Action Constraint Action-EyeBlink - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-LOW03.R
do Action Constraint Action-EyeWide - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-LOW03.R
do Action Constraint Action-EyeBlink - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-LOW02.R
do Action Constraint Action-EyeWide - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-LOW02.R
do Action Constraint Action-EyeBlink - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-LOW01.R
do Action Constraint Action-EyeWide - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-LOW01.R
do Action Constraint Action-EyeBlink - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-UP03.R
do Action Constraint Action-EyeWide - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-UP03.R
do Action Constraint Action-EyeBlink - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-UP02.R
do Action Constraint Action-EyeWide - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-UP02.R
do Action Constraint Action-EyeBlink - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-UP01.R
do Action Constraint Action-EyeWide - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-UP01.R
do Action Constraint Action-EyeBlink - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-CORNER-OUT.R
do Action Constraint Action-EyeWide - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-CORNER-OUT.R
do Action Constraint Action-EyeBlink - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-CORNER.R
do Action Constraint Action-EyeWide - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-CORNER.R
do Action Constraint Action-EyebrowRaise - Ob Rig Chase.001 Pchan TGT-EYEBROW01.L
do Action Constraint Action-EyebrowLower - Ob Rig Chase.001 Pchan TGT-EYEBROW01.L
do Action Constraint Action-EyeBlink - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-LOW03.L
do Action Constraint Action-EyebrowRaise - Ob Rig Cano.001 Pchan TGT-EYEBROW04.L
do Action Constraint Action-EyeWide - Ob Rig Chase.001 Pchan CTRL-TWEAK-EYE-LOW03.L
do Action Constraint Action-EyebrowLower - Ob Rig Cano.001 Pchan TGT-EYEBROW04.L

Even with a dependency cycle for the jaw bone, that doesn't explain why it is spamming the action for eyebrows and eyelids. Why is it happening? How do I fix it?
When it crashes it says this:
Error   : EXCEPTION_ACCESS_VIOLATION
Address : 0x00007FF6915BADEC
Module  : blender.exe
Thread  : 00005340
do Action Constraint Action-EyebrowRaise - Ob Rig Chase.001 Pchan TGT-EYEBROW04.L
do Action Constraint Action-EyebrowLower - Ob Rig Chase.001 Pchan TGT-EYEBROW04.L
do Action Constraint Action-EyebrowRaise - Ob Rig Chase.001 Pchan TGT-EYEBROW01.R

And it repeats the entire Constraint Action thing once more for good measure.
It also mentions NLA Eval: Stopgap for active action on NLA Stack - no strips case some more times. What is that?
I see the Shakify add-on appearing in the debug output from time to time. Could it be part of the problem?
Do you think the dependency cycle could be the problem?
The mouth bones are constrained to bones parented to the jaw bone so I can toggle them following or not following the jaw.

you should file a bug report to Blender with help->report a bug. This is not part of this site.

@Chris I'm not sure if this can be successfully accepted as a bug, since it is not happening with other rigs. You should be able to reproduce issue with a new file.

@Gaja you post a lot of text ... from quick view it sounds to me (I'm not an animator) as a rig  or action issue ... try to delete some NLA actions or part of your rig (mentioned in reports) to see what cause crashing so you can concentrate on that part ... or share your simplified file (delete all that doesn't participate on the issue).

Ok thank you, I will give it a try. I'm sorry if this was posted in the wrong place, I've only ever seen this forum through earlier troubleshooting and didn't know where else to go


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Dissolve collinear points - Geometry nodes
I am looking for a way to remove collinear (in a straight line, I think?) points from a flat N-gon face, with geometry nodes. I can select the desired points with the edge angle node, but I am not sure how to fill the gap left by deleting them. Is there a way to fill the gaps left by deleting, or is there another way, to "dissolve" the points.
Below is an example mesh (extruded to show the points/edges to be removed).

Does this answer your question? https://blender.stackexchange.com/questions/299231/

Yes, that works, thanks very much.


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Is there a function that acts like a camera in the viewport?
The example is a car on a highway.  Keyframed at 2 points and a camera parented to the car.  When viewing from the camera the car is in frame.   When viewing from the viewport the car flies by.
Is there a way to make the viewport follow the car like the camera?  A function that allows the viewport to act like a camera. That can track an object as if it were parented to that object. I noticed that would be very helpful when trying to animate a driver in the car, etc..
This would be a great feature I think if not already implemented.

AH View Lock to Active under the View -> Align View menu.  Ok, I think that's the answer.

There is also an eye-dropper tool in the N-panel.


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Reposition animated rigid body
I made a simple animation of food falling from a bag to a bowl, but this animation starts at frame 0 and I need it to start at 2800.
How can I move it?

Hello you could either recalculate the physics so that they begin from frame 2800 (Scene panel > Cache > Simulation Start):

Or go into the Object panel > Rigid Body > Bake to Keyframes,it will create a series of keyframes that you'll be able to move:


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White light reflections show up as ugly white patches
I have a nicely done texture of a costume. Notice the texture already has 3D effect and nice light reflections. But when I UV mapped it onto the model, they simply render as ugly white patches.   I tried playing around with glossy BSDF mixed with diffused BSDF shading, but they reflect light in wrong places.

How do I improve on this such that the white light reflections render properly as actual light reflection instead of ugly white patches?
Your advice is greatly appreciated!


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Properties menu only has tiny text which is too small to read
In Blender, 3.4, upgraded to 3.4.1.
The text in the Properties menu is extremely tiny. The other menus are fine but the Properties menu is too small to read. Adjusting the resolution in the preferences does increase the menu text but not just for the Properties menu alone - it increases the text size for all of the Blender interface.
Is this a bug?

https://blender.stackexchange.com/questions/282705/the-properties-area-text-is-smaller-than-the-others/282709#comment485810_282709

Your Properties tab is zoomed out. Use Ctrl+MMB (middle mouse button) to zoom in.

You can also use + or - on the numpad  if you have one.

This is awesome. Never knew this existed. I think it had something to do with the imported file. I don't remember changing the window size in this way. But that was the solution. Thanks!

@Powersolo This also works in other software as well, browsers for example.


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Fluid simulation : sometimes not properly baking?
I'm playing with fluid simulations (Blender 2.78b).
There is something quite odd.
When I bake my fluid, sometimes it works, sometimes it acts as if some parameters (inflow velocity ? speed ?) were ignored when baking.
normal baking

broken baking

I didn't change anything between those two versions, the only difference could be that I did animate the "Enabled" checkbox (Fluid tab from the Physics panel), but I'm not even sure I did; I think this is a bug.
Has anyone experienced the same thing / does someone knows why I got this ?
Thanks !

How can you not be sure whether you animated the enabled checkbox or not? Baking will be exactly the same every time until you change something.

I did notice this when making tests with the checkbox.
And I'm not sure that it is why my baking is altered.
Let's say it is enabled at frame 0 and that I disable it at frame 100.
The 100 first frame of the animation should be the same.  And they are not.  As it looks like a bug, i'm not sure that it is related to the checkbox thing or not.

Did you change the fluid cache? There's an option to change where the cache is outputted (under Physics in the domain object), and if you change the parameters and bake again without changing the cache output, it can cause glitches in the new bake, because of the discrepancies between the parameters you changed and the parameters set in the cache from the previous bake.

Nope, I didn't... :/

Oh well, try making a new cache, see if that works.


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How to render a matte with Eevee?
How can I render a matte (white on black or white on transparent) using Eevee ?
What I ask is a type of render that would render faster than a regular one.
I just need the "shapes", not the materials / reflections / colors.
If it exists, I would like to be able to "switch" to the matte render without having to change every material.
Currently, what I do is that I disable all the lamps and objects I don't need, set the world to black color, and set film > alpha > transparent in the render panel.
It works but I guess that there might be a better solution.
Possible ?
Thanks !

If you've already set the World to 'Transparent' then you shouldn't need to disable the lamps or set the world to black - just use the Alpha channel of the output as your matte - it will be 1.0 wherever it hits an object and will be 0.0 wherever it does not. In Eevee, transparent objects will produce alpha of 1.0 (as transparency is only simulated in Eevee).
For a faster render you could switch off unnecessary features (that don't affect the Alpha render) such as Screen Space Reflections, etc.

But then it will need to "compute" every image with the lighting, etc, no ? There is no way to just render the "silhouettes" of objects (plain white color) so it renders faster ?

If the lights are there then Blender is going to consider them for lighting - but if you're rendering the scene normally anyway - as well as needing your silhouettes - then the Alpha will be produced as part of your main render without any additional effort. If you do need to render only the silhouettes then you'll need to disable the lights and turn off any additional features (such as indirect lighting, screen-space reflections, etc.) for additional speed of rendering.


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mask layers : are they ignored by freestyle?
does freestyle ignore Mask Layers from the Renders Layers tab ?
I have checked the layers I want to be used as masks, but it doesn't seems to work.
The only way I found for now is to duplicate some meshes on my freestyle layers so that they hide the freestyle lines.
Is this a bug or am I doing something wrong ?  Thanks !

I have a similar issue, freestyle strokes are only applied to one render/view layer.


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How to Match Clothes Rig to Follow Character Mesh Movement (Blender 2,7)
I tried to animate character with clothes but the problem is the clothes won't follow up the body movement. Like for example, when i wanted to bend the knees, the trouser can't bend like the knees do. Here's link to my blend file if anyone can help with it: https://drive.google.com/file/d/1fu9UDFFM2cGUHXtMYyaBrbIhs4Ec6mXF/view?usp=sharing
Also, if there is a good video tutorial about it please tell me. I'm just started using blender and didn't know much of how to use it.

to begin with, the clorhes have not beed parented to the armature, so it can't follow

Side note: Consider upgrading to Blender 2.83 LTS if your hardware fulfills the requirements. The UI was redesigned in the update 2.79/2.80, also some shortcuts have changed. The shortcuts mentioned here are for 2.8+
First, you need to parent the cloth to the rig as you did with the body mesh with Automatic Weights. Then it will deform but there are still some issues.
The Shirt
It has a different, not ideal topology. There are some loose & duplicated verts. The different topology will cause a lack of volume in the shoulders.

You need to fix it (delete one side, fix the verts, and apply a Mirror modifier).  Or create it from the scratch. A common technique is to select the faces of the body mesh, duplicate them and separate these faces to a new object. Then scale up the shirt a bit and inflate/widen it. This way the topology fits the body's topology.
Add a Soldify modifier if you like but make sure the Armature modifier is on top of the stack.

Skin is sticking through the cloth
As you can see there is still some skin sticking through the cloth especially when the Subdivision Surface modifier is active and the mesh is deformed by the Armature modifier.
To prevent this you can do manually correct the weight paint and mask out the body mesh with the Mask modifier. Select the faces that you want to hide and assign them to a vertex group. Then add a Mask modifier, specify the vertex group and click the Invert <-> button.

How to fix knee bending
To get a better bending of the knees you need to add a bit more geometry to the legs. If you have a look at the elbows you will notice that they have 2 extra edge loops.
The simplest method to get a better deformation is to add 2 more edge loops. For a better result, you want to give the kneecap more geometry and the back of the knee less so it can compress better. There are several methods to do this. Here are two for a low-poly mesh as your model has:
Variant A: Add two edge loops, create 2 triangles at the sides with the knife tool K and X, Dissolve Edge:
Variant A with Subdivision Surface level 1

Variant B: Similar to A but insect I the front face to add a knee patch.
Variant B with Subdivision Surface level 1


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How to get rid of these splits on my donut icing?
So I am new in blender and I was about to do the icing of this donut and I noticed that there are these kind of split openings on the donut (also it looks weird inside) -it’s kinda not really smooth it looks like as there‘d be 2 layers of the icing I would be really grateful for help or advices

A my hello is missing on the top @.@

perhaps we just see the faces of the object underneath?

@moonboots a yea I thought that too but on the tutorial which I’m doing this from were non of these (I hope I didn’t misunderstand you)

maybe he has given a Solidify modifier to his icing?

A just checked it and yes he did and I just do it too but now it looks even weirder

make sure that all the normals of your faces are correctly oriented (select all in Edit mode and press Shift N) and also try a negative thickness value in your Solidify (or positive if it was negative)

if it still doesn't work please share your file: https://pasteall.org/blend/

Okay thank you so much I’ll try it!


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What are these Black textures on my donut?
So I was working on a Donut (following a Tutorial on YouTube)and Theres keep coming thus weird black texture on it. I have re-made the donut too and it still appears…I‘d be thankful for help or any advices!

hello, maybe the faces of the object underneath that are overlapping?

A I’m sorry I don’t really know what you mean by that may I ask what I should do?

what happens if you select the donut, go in Edit mode, move its top faces down?

I separated them and then it’s gone but once they come together it’s back

OH OH it’s gone idk how but it left aa sorry for wasting your time, thanks!!

:D this effect that @moonboots introduced you to in a way is called "Z-fighting". It's and artefact caused by imperfection of the calculations done by the 3d engine - 3d engine as its "common" issue between different 3d engines. As your screen is in the end a flat 2d canvas, there are series of functions that will translate virtual 3d objects onto that canvas in a way that it will try it best to represent depth and perspective. But, as there are sin and number Pi involved, and to be efficient 3d engines cant use to many decimal numbers, some approximation do occur.
When there are 2 virtual 3d surfaces overlapping, due to the approximations, render engine is not sure which pixel of each surface is in front and which one is in back - hence the weird artifacts
https://en.wikipedia.org/wiki/Z-fighting

Oh oh I found a solution thank you for the explanation


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Loop cut and change color problem
In edit mode, when a cube is loop cut and divided into two faces, one face is selected and the color is changed, but only that face needs to be changed, why does the other face change color

if you want to give another to this face, you need to give it a new material (in the Material panel, click on the "+" button on the right of the material list, then press New...

As you only have one material applied to the cube mesh (Material.002), this material will be applied to every face of the cube. If you want different colors in your cube you must first create different materials in the Materials Properties tab, by clicking the plus + button:

Once you have multiple materials created, you just need to assign them to the desired faces of your cube. In edit mode, select the faces, select the material and click Assign:

Thank you for answer!


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In UV Editing vertex problem
I have selected all the vertices, but why is only one vertex visible?

Hello, maybe unwrap again?

Thank you! I solved it.


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Render looks flat compared to view port camera
Did a landscape scene with TXA LANDSCAPE add-on in blender. The mountain looks fine in the view port but when I render the scene it looks like a pyramid or the shape it looks like. I am a beginner and I don't have much experience. Thank you.

Hi Tamil, I am not familiar with this add-on but it looks like there is difference in the Render and Viewport subdivisions settings of the Modifier(s). The first thing to try is  checking them and to make sure the Render subdivisions are equal or higher than the Viewport subdivisions.

@RumenBelev thank you so much for your answer. increasing the render subdivisions fixed the issue.

@RumenBelev please add your comment as an answer so that you can get credit for it.


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Why am I getting banded stripes in my reflections?
I've been using blender for about a week, so I'm still very much a beginner - I'm trying to make a roll of plastic for my website, I'm having a problem though, in that my reflections are showing strange bands.
I'm aware that I need to increase my render samples (the screenshot is to illustrate the problem), but this doesn't remedy the problem.
Anybody got any ideas?

Try setting the shading to smooth from the tool shelf (t). If that doesn't work then check your normals or do recalculate outside for the normals. If that doesn't work either check your model for errors, overlapping faces etc...

Overlapping faces........you Sir, are a legend. Thank you!


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Import DAZ3D facial expressions
I’m able to import a pose to Blender but the facial expression doesn’t come with it. I've tried some things I read online but none resolved this problem.
I’m using Diffeomorphic to import the poses but when I import it doesn’t apply the facial expression! Did I miss a step?

Sorry, but on this site we are answering questions about problems using Blender and its officially shipped addons, for third-party addons please ask respective developers. Also on the Daz3D site there are discussion forums regarding Blender and Diffeomorphic.


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How can I make triangular form holes on a sphere?
I need to create a particular sphere which has 4 holes with a triangular form on its surface. I know that I can use boolean modifier, but my problem is that I want to maintain a good topology because I will use this model on an engine. So there are other solutions which allows me to have good topology?
This is a reference of model I want to make:

Hello maybe show a reference image of how your sphere should look like?

Perhaps a stupid idea : start from an Ico Sphere already made of triangles ?

Hi, Illidonn, welcome to BSE. We need an illustration (even a messy version) of your desired result. Quite a few variables, here :)

@StefLAncien my first thought, too.  or perhaps one of the Geodesic Dome variations.

I'm going to change my proposition so that it matches your reference image

Here's my way: turn a cube into a sphere with Cast modifier; connect equidistant vertices (e.g. those circled) with J or its counterpart in your version and then repeat the procedure three times to make the remaining three triangles. The image below shows it.

Create this mesh, mirror and array it:

Give it a Simple Deform modifier, Bend mode, 180° on X:

Then another Simple Deform, Bend mode, 360° on Z:

Former answer:

Beginning with that knife cut and then join vertices, extrude, bevel, etc:


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How to copy one model pose to another?
I would like to change the position of the bottom model to look like the one on the top.
Is there anyway to do this automatically? Without manually adjusting the bones? They are completely different models from different sources.

Hello, is the armature the same (same bones with same names)? If not I don't think that there's any trick, you need to pose it manually

hey, yeah they are not the same bones neither the same names.  So posing is my only option for this task?

I guess so but there may an option that I don't know

will see other replies! thanks a lot anyways!

Is the bottom skeleton in default pose? If not, selecting all the bones in pose mode and hitting alt+R and alt+G will reset the pose. This might look more like the default T pose on the top model.
You could also rename the bones so they have the same names as the bottom model and copy-paste the pose. Even  if it's not the same bones presumably the skeletons have a similar structure on the hands and arms

yeah the bottom is also in default pose its just the arms and hands bent like that. I could try that but the number of bones is also significantly more.  I have to align that model cause im trying to do a character replacement mod for a game lol.


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Avatar's skin stretches when moving the armature in pose mode
I've finished rigging an avatar and, as the title suggests, whenever I try to move the armature in pose mode, the avatar's mesh from the feet and hands stay in place, stretching out the skin.

I think it might have something to do with the control bones since when I move the bones and control bones too far away from each other,  Any tips would be great!

Just a guess: You have forgotten to disable the Deform option for your control bones and made them deform bones. If yes, then uncheck the option and delete the vertex groups with the same name as the control bones.

@Blunder So I've un-deformed the control bones, and it worked fine for the hands. The feet, not so much. Not sure what a vertex group is, though. Where can I find it?

The vertex groups are in the Properties panel > Object Data Properties tab (right side on the screen below the outliner) => https://i.sstatic.net/veXQe.png -- If you don't know which bone is the bad one you also can check the weights in the Edit mode. The weights are displayed in the viewport's side panel (key N to open it). Have a look here: https://blender.stackexchange.com/q/156882/107598


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Texture gets distorted while rendering
Before rendering, my project looks like this:

When I render it, the visuals get distorted. What can I do?

Looks to me like there's a duplicate cylinder object on top of your barrel. Look in your outliner (the UI element that shows a list of all the things in your scene.)
Are there objects there that are hidden? It is possible for an object to be hidden from the viewport mode, but still appear in the render.


text:
add custom texts(labels or annotations) which are always upright to user in view port
I would like to put some user defined texts(labels) besides bodies as annotations, those texts(labels) are always perpendicular to user, which means whenever I rotate or scale the object, those text's size are always the same and there orientation are always upright to the user, just like the "x,y,z" in the left bottom corner of the 3D view, see the screen shot below(pointed by red arrows).

If you use the "Ruler/Protractor" tool, you will see same kinds of texts(lables) can be added by those tools.
Any ideas about this kind of text, I need such kind of text to demonstrate the models when teaching. Thanks.
EDIT: Looks like this post https://blender.stackexchange.com/a/1606/2722 give me some ways to workaround this issue, but I definitely need a clean way.
EDIT2: Now I can correctly display a text attachment to an object in the view port. But the text is not user defined, I means I can show a matrix or a object's name, but is it possible to show a customized annotation text strings?

Labels in Render
An easy (but limited) way would be to parent the text labels to the camera.

Select text label RMB
Add camera to selection Shift-RMB
Set camara to parent Ctrl-P

After that movement of the camera or transforming the objects in the scene would no longer influence the appearance of the label.
Example rotating object and moving camera:

Labels in Viewport
If you want to draw labels in the view port you find all you need in Adhi's display_matrix.py script.

Thanks, but the added text is still a mesh, is it possible to directly a text by some python scripts, so it will shown just like the texts generated by Ruler tool.

That's pretty nice. I just wonder if the font size can be adjustable for the script.

Thanks stacker, I just download it, but I don't know how to use this add-on, any one can help me? I can't find much document about its usage.

@ollydbg23 The add-on was intended as a demonstration of the API calls required to add text labels to the viewport. As far as I understand your question you probably want to add text as object properties and display them close to the object perhaps with an offset to the center. You load the script into the text editor, press Run Script, a new section appears in the view ports properties panel ('N').

Hi, stacker, I follow the way you suggest, and now I have a "Display Matrix" section in the view ports properties panel now, thanks.


text:
Geometry Nodes: How can I target each spline individually in a curve object?
Let’s say I want to build ladders with geometry nodes, using a bezier spline as « main » object.

I would duplicate the spline to have two rails
and add points on the curve to instanciate the ladder’s steps.

The first (index=0) and last point (index=point count-1) would be ignored for the steps instances, as those are the extremities of the ladder.
This works great.
But what if I have several splines in my curve object; because I want to have several ladders generated ?
This does not work anymore; as I can’t target the first and last point of each spline.
I’m searching a way to have Geometry Nodes considering each spline individually, and have the whole logic based on each spline.
Is this possible ?

why don't you just instantiate your "ready" ladders on e.g. geometry on points node? maybe a sketch would help what you want to achieve... ;)

...I was just thinking of the exact same thing @Chris brought up.

@Chris : edited with a picture...

i have no idea what you wanna make, but hopefully this helps:
i made ladders from beziercurves, and i put ladders on points of beziercurves:

As a safety inspector: this is a nightmare; but visually it's pretty cool  – a ballet of ladders.

@MarkusvonBroady: Thank you very much, i appreciate that!

@MarkusvonBroady & Chris, And I'm not a ladder expert, but I like your recent friendly interaction with each other ;-)

I think you're looking for the Endpoint Selection node.

Using default parameters will remove the first and last point of each sub-spline.

This seems great ! I managed to remove points on a curve.  But this doesn't work to remove points after a "curve to points" node.

I guess you can transfer the information as an attribute by index or proximity from the curve to the points ?


text:
geometry nodes : limit to X edges connecting each vertex
I have this mesh generated through Geometry Nodes.

Is there a way to delete edges, based on a maximum number of edges connecting each vertex ? I want to achieve something similar to the Plexus plugin for After Effects, which has (among others) this option.

In my case, this might filter edges to get something like this:

I’ve seen the Vertex Neightbours node, which can output how many edges a vertex has, but once I know that, I don’t know how I can remove some n-1 edges.
Thanks !

"I would like to keep only one edge maximum connecting each vertex." ...and what is the criterion according to which the correct edge is selected, should several edges be connected to one point?

For now, I would like to find a way to limit to X edges conneting a vertex (like you can on the Plexus plugin for After Effects). No specific rule. Later, i’ll try to filter some of the edges depending on their angle…

In principle, you could achieve this with the help of the node Vertex Neighbors or Edge Angle. However, it is still not clear to me what the final result should look like.

Thanks @quellenform, question edited.  I’ve already checked Vertex Neightbors - which is helpful but I don’t see how to remove the « extra edges » after that.

OK, I see, but what is still not clear: What rule defines which are the "extra edges"? For example, in the center of the image there is a point connected with nine edges. Which of them is the "extra edge"?

I don't know how to "rule" that.   The one to keep might be the first one in the spreadsheet list, or a random one.


text:
physics : inflate a mesh until it reaches the limits of its container
I have a room scanned from a photogrammetry.
I would like to grow a mesh (like a baloon inflating) inside this room until it reaches the room boundaries.
The goal is to have a mesh that would be the "negative space" of the original photogrammety, and then to print that mesh.
Would this be possible ?

Do you mean something like this https://forums.sketchup.com/t/need-to-create-an-inverse-or-shell-of-a-3d-surface/15405/8
and
https://global.discourse-cdn.com/sketchup/original/2X/9/9ed109b7878d12affd07c13727e2623bae42fe8a.gif

Also https://blender.stackexchange.com/questions/72612/how-to-turn-a-mesh-inside-out-like-a-sock


text:
How to rig an eyelid for a (perfectly) spherical eye?
i'm trying to find a way to build a good but simple rig for an eyelid.  It's for a robot, so the eye will be perfectly spherical.
Actually, I just have two demi-sphere rigged on an "up" and "down" bone, so I can open and close the eyelids.
But I want it to be a bit more complex; so I could animate the "open" shape of the eyelid and give him some extra emotions.

How should I handle this ?
I had some tests using a (flat) plane that would be "projected" on the sphere (shrinkwrap or cast modifier), but it's not deforming smoothly.
Or maybe I should use shape keys somehow, like in this example:

But I would have rather loved to be able to control that with bones.
I would be glad to get your advices.
Some tutoriels I've seen :

Rigging and Animating Cartoon Eyes with Shape Keys in Blender 2.9 (nice but no way to act on the "open" shape)

Eye Lid Mask Rig In Grease Pencil almost what I would like in terms of rig, but it's flat - not spherical

Thank you !


text:
How to call Operator when WorkSpaceTool is activated？
import bpy

class SimpleOperator(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "object.simple_operator"
    bl_label = "Simple Object Operator"

    def modal(self, context, event):

        print("do something")

        return {'FINISHED'}

    def invoke(self, context, event):
        print("invoke")

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

class MyTool(bpy.types.WorkSpaceTool):
    bl_space_type = 'VIEW_3D'
    bl_context_mode = 'OBJECT'

    bl_idname = "my_template.my_tool_test"
    bl_label = "My Tool Test"
    bl_description = ""
    bl_icon = "ops.generic.select_circle"
    bl_widget = None
    bl_keymap = None

def register():
    bpy.utils.register_class(SimpleOperator)
    bpy.utils.register_tool(MyTool, after={"builtin.scale_cage"}, separator=True, group=True)

def unregister():
    bpy.utils.unregister_class(SimpleOperator)
    bpy.utils.unregister_tool(MyTool, after={"builtin.scale_cage"}, separator=True, group=True)

if __name__ == "__main__":
    register()

How to call Operator when MyTool is activated？
This is the effect of primitive_cube_add：

I don’t want to register bl_keymap, it requires at least one mouse click to call Operator


text:
about selecting all visible elements in editmode？
I checked some information and got the following code：
def visibleElement(context, bm):
        area = context.area
        spc = context.space_data
        sel_mode = context.tool_settings.mesh_select_mode[:]
        show_xray_wireframe = spc.shading.show_xray_wireframe
        spc.shading.show_xray_wireframe = False
        bpy.ops.mesh.select_mode(use_extend=False, use_expand=False, type='FACE')
        bpy.ops.view3d.select_box(xmin=0,xmax=area.width,ymin=0,ymax=area.height,wait_for_input=False,mode='SET')
        context.tool_settings.mesh_select_mode = sel_mode
        verts = [bmv for bmv in bm.verts if bmv.select]
        edges = [bme for bme in bm.edges if bme.select]
        bpy.ops.mesh.select_all(action='DESELECT')
        spc.shading.show_xray_wireframe = show_xray_wireframe
        return verts, edges

Is this the only solution？To be honest, I don’t really want to use select_box, but there seems to be no other solution.

AFAIK using box select operator as above in edit mode is probably the simplest, and likely quickest way to do this.  Other methods would involve eliminating geometry by  looking at normals, and further eliminating via raycast or some such in case of occluding geometry.

Ok thanks a lot


text:
How to remove aliasing in gpu drawing？
import bpy
import gpu
import bgl
from gpu_extras.batch import batch_for_shader

from math import pi, cos, sin, ceil

if hasattr(bpy, 'test_handler'):
    try:
        bpy.types.SpaceView3D.draw_handler_remove(bpy.test_handler, 'WINDOW')
    except: pass

def base_radius(segments):
    radius = []
    m = (1.0 / segments) * (pi * 2)
    for p in range(segments):
        radius.append((cos(m * p), sin(m * p)))
    return radius

segments = 20
part = 1
if segments % 4 == 0:
    part = int(segments / 4)
else:
    part = int(ceil(segments / 4))
    segments = part * 4

baseRadius = base_radius(segments)
baseRadius.append(baseRadius[0])

radius = []
for i in range(4):
    start = part * i
    end = part * (i + 1) + 1
    radius.append(baseRadius[start:end])

def get_area_height():
    height = 0
    for area in bpy.context.screen.areas:
        if area.type == 'VIEW_3D':
            height = area.height
            break
    return height

def rounded_rectangle(x,y,w,h,r):
    """圆角矩形"""
    if 2 * r > w:
        r = int(w / 2)
    if 2 * r > h:
        r = int(h / 2)
    coords = []
    for index, item in enumerate(radius):
        for m in item:
            ox = x + w - r if index in [0,3] else x + r
            oy = y - h + r if index in [0,1] else y - r
            p1 = ox + m[0] * r
            p2 = oy - m[1] * r
            coords.append((p1, p2))
    print(coords)
    return coords

area_h = get_area_height()
x = 100
y = 100
cos =  rounded_rectangle(x, area_h - y, 100, 100, 20)

shader = gpu.shader.from_builtin('2D_UNIFORM_COLOR')
batch = batch_for_shader(shader, 'TRI_FAN', {"pos": cos})

def draw():
    shader.bind()
    shader.uniform_float("color", (0, 0, 0, 1.0))

    bgl.glEnable(bgl.GL_BLEND)
#    bgl.glEnable(bgl.GL_POLYGON_SMOOTH)
    batch.draw(shader)
#    bgl.glDisable(bgl.GL_POLYGON_SMOOTH)
    bgl.glDisable(bgl.GL_BLEND)

bpy.test_handler = bpy.types.SpaceView3D.draw_handler_add(draw, (), 'WINDOW', 'POST_PIXEL')

How to remove aliasing or lines？

Related https://blender.stackexchange.com/questions/230545/rounded-corners-for-2d-rectangle/231170#231170


text:
How to select side of active vertically?
Does the side of active from select (Edit mode) also select upward/downward vertices?
It seems like it only selects the left right sides...

Use the Z axis option.

@lemon Where are the options? I'm just doing Select -> Side of Active, which doesn't seem to pop up an options window or anything.

that should pop up a 'select axis option'.


text:
When I render the color disappears
I am very new to Blender. When I render the image, the color that it used to have disappears.
This is the color it has in Solid mode:

And this is in Material Preview mode and when it is rendered:

I am using EEVEE engine.
Blender file:

Could you provide your Blender file using https://blend-exchange.com/ ? Do you have materials defined in the Material Properties panel ?

Hi. Please don't post essential information like links, file downloads or additional details in the comments section where it can be easily missed. Instead edit them into your original post with the [Edit] button above. Comments are transitory by nature, are hard to index or search for, and may be erased at any moment.

The rendered view needs materials. You don't have any materials.
You just have a color attribute, which you defined on the face corner as color:

if you create a material like that:

you will get your color.
Then select all objects and the object with the material at last, ctrl-l -> Material.
You need two materials or you rename your attribute - because sometimes you named it "Color" and sometimes "Attribute".

oh it solved! thank you so much!!

you are welcome


text:
Big difference in rendered appearance between Blender 3.6.4 and 4.0.2
I created a scene in Blender 3.6.4 with some primitive shapes and some simple lights and little bit of compositing:

It rendered well in 3.6.4, like this:

However, with the same settings in 4.0.2, it's very different:

If anybody knows why and how can I fix this, please share.
Both rendered  in cycles
Color management settings:

They're the same.
The .blend file:

Your Point lights have radii of around 2.5 meters, which means they are intersecting the glass objects. They are doing that in the old version as well, but the way the light works was changed.
The behaviour of Point and Spot lights have been changed in 4.0 to be more adequate representations of real life spherical light sources (which does not make sense for spots which I said in a discussion on Blender Project, but anyway) regarding energy conservation and the casting of soft shadows. I'm no physicist or raytracing expert to judge on how much this is true, it's just what was explained by developers in the discussion.
Take a simple setup, a 2×2 m default plane object, then place a Point light directly at its center. I'll give it a Strength of 50 W and a Radius of 0.5 m:

Looking at it top down in rendered view shows the following differences:

The radius on the older version made the shadows softer, but the new version makes absolutely sense because if you would have a brightness falloff within the radius of the light source (like the old version), it would behave as if it was an infinitely small point of light. But if that was the case, it would not cast a soft shadow. So the new version keeps the brightness consistent until it reaches the radius and then you have a falloff - and this makes more sense for a soft shadow as well.
Think of the new Point light with radii > 0 like they are some kind of light bulb with frosted glass. Of course in reality there is a light falloff between the filament and the glass, but you cannot see it from the outside (or only to a certain extent).

thank you for your detailed answer, I definitely consider this point in my future works with blender...it's really interesting though, that they made this change after so long...

Thank you too.. I wasn't aware of this. :)

@HassanRostami Yeah well, I don't know who came up with this and why now. Maybe because they do major changes only between major version steps, like going from 3.x to 4.x...

@RobinBetts But in November you thanked me for my research on the topic of the new light behaviour ;)

Ahhh ... senior moment. Nowadays I need telling 3 or 4 times :( This little sting should fix this one :)

@RobinBetts I know, a few times are needed nowadays... I'm not sure who's really the senior here ;)


text:
How to set different lengths of animation for different objects?
I have made an animation for two different objects, say a cube and sphere, and I gave different keyframes to both objects.
For example: I gave total keyframes of 30 to the cube and 50 to the sphere. The end keyframe is 50. Now, when I hit the animation, the action starts and cube remains still after 30 keyframes. However, I don't want that.
I want the cube to come back to the first frame after it has crossed 30 keyframes without waiting for the sphere of 50 keyframes to be completed.
I shared my blend file

You cannot have that. You can add a Cycles modifier to the cube animation so that it repeats after finishing, but then the next cycle will be finished at frame 60, which means the sphere animation will stand still. If you repeat that, it goes to 100, so you have to make the overall length the lowest common multiple. However, what you are asking is like watching a movie, and when one character dies halfway through, the end credits should roll, while the movie moves on for the living characters. That's not possible. The Timeline  is the movie, cube and sphere are the characters.

Select the Cube's keyframe in the timeline at frame 1 and Ctrl-D to duplicate it. Then drag it to frame 50 and run the animation to see if that does what you want.

Thank You But my question is how to apply different timeline length to different objects in same file?

I don't really understand that. The timeline is the same length for all the objects in your scene. You can't have different timeline lengths for each object. If you want the cube to jump back to its rest position after frame 30, just drag the last keyframe back from frame 50 to frame 30.

I reckon you can sort-of do that with the NLA editor but that'd be more complex than just duplicating a keyframe.

@L0Lock Yes I suppose you could, but like you I can't really see the point to be honest.


text:
I can see the full sea in view port but on camera view I can see only half of it or less
I am trying to do ocean 200m on the view port I can see it fully, but on camera view I can't see all of it, only half or even less.
What is the problem here? How can I make it full render on view port?

well....you question isn't totally clear. Maybe lemon's answer is what you want. Maybe you aren't aware, that your viewport (as you show it in your image) has other aspect ratio than your camera - which is the render resolution. So if you change that and move your camera, you can get the same as your viewport.

thank u for replying yes i ddint notice

As the viewport has, the camera has its own clipping distances:

thanks lemon , yes it worked i didnt reply cuz i dont wanna answer here its not for the rules i reckon but i appreciate it


text:
How could I setup a « video feedback » effect ? (camera filming its own output)
Someone asked me about a great challenge here: is it possible to create a « video feedback » effect in Blender; like this one:
My scene setup:

camera A pointed on a human.
Behind the human, there is a screen; which « streams » what camera A captures.
So this would create a video feedback effect.
That whole scene would be captured by camera B on a larger shot; and this would be my final output.

My first approach was to check if there is a « camera output » node (for the screen material) to feed the screen material, but there isn’t.
I searched the web and found this:

Create texture dynamically from camera view… possible? (Blender Artists)
Use file output node for video feedback - can it be done (Blender Artists)
Render to texture (Right-Click Select)
Video feedback loop - animation test - Blender (seems someone managed to do it in 2015)

But no real solution.  Someone wrote a python script, but it has been done in 2015 for the Game Engine, so i’m not sure I could use it here : Render To Texture - Game Engine.
Another solution I see it to do it manually, but that is quite long/boring to do!
I can't imagine rendering an animation manually like this...

screen texture: (none) >>> render cameraA to cameraA-001.jpeg
screen texture: cameraA-001.jpeg >>> render cameraA-002.jpeg
screen texture: cameraA-002.jpeg >>> render cameraA-003.jpeg
screen texture: cameraA-003.jpeg >>> render cameraA-004.jpeg
screen texture: cameraA-004.jpeg >>> render cameraA-005.jpeg
Finally, render the camera B view.  I would have a loop of 5 « iterations » in the screen.

Back plane is a "screen", bottom and right planes are mirrors.

So, is there a way to script this or is there another way to achieve it ?
Thanks a lot !

I was just thinking about that after Tom Scott said it wasn’t possible. My thought was to use compositing, but I’m not sure if compositing can reference a different point in time. I think it can, or at least it could probably pull up past rendered frames.

But why wouldn't it be possible to script my "manual" solution ?

oh, I didn’t say that. Scripting was my first thought. I just like to avoid scripting cuz for me I feel I’m in the jerry rig phase: any slightest change in the API or purpose would bring it crashing down.

Sorry, I had misread your first comment :) Ok ! I'll try to find out...

How about this https://blender.stackexchange.com/a/213637/29586 ?

You mentioned doing it with multiple renders.  This can be optimized beyond what you imagined (but still requires 3 images, in 2 separate renders, for every frame).

The first thing we'll do is set up an AOV.  For our video monitor, we'll output UV in this AOV.  For everything else, we'll output RGB 0,0,1.0.  This will let us distinguish between the screen and everything else in the render, and will get proper occlusion of the screen.  Let's render both this AOV and our actual rendered output (minus the screen).
Now let's set up our screen material in a little more detail.  We haven't worried about it yet, because we'll be replacing it:

Make sure you understand what we're doing here.  We're using the screen's UV to look up both renders.  If and only if the AOV render is blue, we mix in the color from the render.  This is our first pass.  Now let's make a node group out of it:

I've added a few details to this node group, so it needs some explanation.  I've given it a vector output, which is the RG lookup from our AOV render.  I've created a "stop" input, which mixes us back into our original color if it's set.  And I've created a "stop" output, which is set if either our stop input is true or if our AOV lookup reads Blue.  Notice that the inputs and outputs and now perfectly parallel.  That let's us do this:

By chaining the node groups together, we can dive as deep into the render as we want, without making any new renders.  Here, I'm doing 4 iterations.  Unfortunately, there is no right number of iterations, and you can't do infinite iterations, but at least it is very simple here to add more iterations as needed.
Note that there isn't any kind of antialising going on.  I'd recommend that you render your AOV at a higher resolution than your final render to compensate.  This should be easy enough because you can render your AOV in Eevee, with 1 sample, so the AOV is a very fast render.

This answer is amazing.  I’ll take some time to try this !


text:
Could Artificial Intelligence be used with Geometry Nodes?
Just by curiousity, I was wondering if it was possible to use artificial intelligence, or complex algorithm (eventually online services) alongside with Geometry Nodes ?
For instance, would it be possible to compare a curve with a library of presets (or models or I don't know the right term) to check if there is a match ?
Then, using the compare node, we could do specific stuff depending of the result.
This would open to a lot of incredible things :)

Geometry Nodes are currently as far away from intelligence as the sun is from the earth. I don't think it can be possible until you can finally integrate a line of code.

Not sure why you need Geometry Nodes for that. Blender has Python API. It sounds like probably most of the stuff one would do with AI would be quite specific and so even with very mature functionality of any node system it would still probably make more sense to program whatever you want to do instead of using nodes.

Ok, I didn't knew it wasn't possible yet(?) to work with custom scripts in GN.

Artificial Intelligence is a very broad term. Anything that in any way resembles human intellect falls into that category, so basically any automation does as well. However, you probably mean some deep learning algorithms, and the question could be generalized to using in geonodes any kind of an external program or library.
Geometry Nodes is a system programmed in C and compiled as part of Blender, that allows you to design a logical structure in a visual way - nodes - and also is able to traverse that node tree and based on that structure call particular functions passing the values from one function to another in the way described by the links between the nodes.
So if you want to use an algorithm that is not already programmed as a part of geonodes source (may be a part of Blender still, or may be an external program), you need to figure out an interface to communicate with it. Other than modifying the Blender source and adding your own "hook" by creating a custom node that then communicates with an external library, you can use a Python script.
You can, before or after the evaluation of a Geometry Nodes modifier, run a Python script. You can pip install any module, as well as you can use C bindings to run any external library. It may be connected to geonodes as a driver that controls a simple value (e.g. you can have a library that recognizes if an object resembles a dog and just drives a boolean value), or you can before/after the evaluation of the geonodes create some more complex data structure, that the goemetry nodes understands and can communicate with - for example by modifying a mesh of an object the geonodes setup reads from, kind of like I do in this answer. Keep in mind the value will be shared for all instances of the node tree, it will be evaluated once per tree per frame (not per modifier per frame).
Of course Python can also read the current object's state by accessing its evaluated state using evaluated_get() on the object.


text:
Trying to find a way to connect points from a point cloud depending of several conditions
I would like to build a little experiment with Geometry Nodes.
I have a curve, with a Curve to Points node.
My goal is to connect some of those points, depending on some conditions, like

no connection from/to the first/last point (easy one)
a point cannot be connected to its previous/next point (it would just redraw the initial curve)
a connection angle should be within a certain angle range

Shortest edge trick
I had an attempt by implementing the the shortest edge trick, and it works, but not as expected : in my example, the shortest edges filtered are the ones that "belongs" to the original curve :

I'm not sure that this technique could be used here, or how could I filter only the "good" edges ?
Maybe that the way to achieve this would be that, for each point, I iterate the other points to eventually find a match.
But can Geometry Nodes do that ?  Maybe with the shortest edge path node  like in this video ?
Any tips ?
Thanks !

Maybe this trick will help you with the second step: https://i.sstatic.net/l6t4R.png (...this is taken from this answer here: https://blender.stackexchange.com/a/263987/145249) The third step could then be done using the node Shortest Edge Paths or via filtering the direction vector.

Thanks @quellenform, your shortest edge trick is badass !!!  But I'm not sure it applies in my case, or at least I'm wrong filtering the edges.  I've edited the question and added a blend file if you have some ideas !  Thank you !

You are right: "The shortest edge trick" doesn't help here, because you don't want to have the shortest edge. In your case it's more about the question how to create a triangulated mesh from the point cloud, hence the link from before.

What I would need would be to use the shortest edge trick on a per-point point cloud. right ?

According to your specification there is no limit of edges, so not only "the shortest edge" is not the right approach, but "the 2nd shortest edge", or in fact any number of shortest edges wouldn't be correct either. You're looking for an angle, so you simply need to create a quadratic search (kind of like in the sorting algorithm, quellenform will know), where for each edge you search among all other edges, and then check if A. they share a vertex, and B, the angle between those edges is correct.

I misread the problem, if all possible edges aren't there to begin with (and the shortest edge trick, if I remember correctly, relies on convex hull and will not work for concavities...) Then you need to create edges between all pairs of vertices, maybe with some length limit, but you will get "overlapping" (in a 2D projection) of a lot of edges probably.

No, "The shortest edge trick" has nothing to do with a convex hull (that was only relevant in the other question). And I repeat the comment from before: this is about creating a triangulated mesh from a point cloud (see first and second comment!).

@quellenform whoops! My bad.

this might perhaps be a way to do it: https://twitter.com/5agado/status/1505591794746241039 - but I don’t know how he achieves this..

@gordie To me it looks like he is moving two spheres here, and moving their points with transfer attribute to the nearest point of the other mesh. After that, he just randomly distributes points on the resulting surface. Just a guess. Try it.


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Trying basic walk cycle. Poses not applying properly from pose library
I am attempting a basic walk cycle for a model I have rigged with Rigify. I am struggling with several things.
Firstly, when I try to apply poses I have saved, they all appear to apply as the same pose - a contact pose. This happens even though in the thumbnail, they are clearly different poses. I have selected all the relevant bones when creating the pose assets.
Secondly, when I hit "create pose asset" from within the Dope sheet, all my previous keyframes disappear, leaving only new ones on the keyframe I've created the asset on.
Lastly, I can't find any way to delete pose assets I've made. Pose library getting clogged as a result.
Any help hugely appreciated. I will add my blend file to this query.
The poses I'm struggling with are all of those labelled as "Walk v2".

Is there a blend file added to this question? -- Have you created the poses first and do you want now to create a walk cycle from it? Or do you try to create the poses while you create the walk cycle? -- Just a few notes: the pose library only supports single poses for now. In the future, it is planned that you can create short animation strips. For each pose, an action with 1 frame is created. The frame has the keyframes for the selected bones. To create and to apply the pose the bones must be selected. The camera & the Workbench engine is used to create the preview image.

Related question: How to delete pose created in new pose asset library blender 3


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Lock edges in their original position
These two models are parts of LOD files:

I want to shrink one of them down (lodcutw09) and this is a selection that I want to shrink down a little bit:

The problem is, when I use the shrink tool on that selection, it also moves position of the edges:

Is it possible to lock all the edges in their original place so they won't change their position at all? Because if they do, they form small holes in the map. Or maybe there is a different way of doing this?

The question is not formed well enough. It's unlikely that you can receive meaningful help with your problem with formulation like this. Edit the question and communicate your problem better. Add more images and descriptions that could let us know what your goal is, also explain how you attempt to "shrink" the model. If you make a screenshot, do not cut parts of it off, so people can see your settings. It might be Proportional editing, that might be causing parts that are close to selected ones move as well, but we cannot see if it's enabled.

You've probably got duplicate vertices there. Try removing doubles first.

Deselecting all bottom vertices solved the issue!


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How can I create this asymmetrical shape and also curve the shape around a 90 degree axis?
I am trying to create this shape (A) and then once created add a curve to it, so that from the top elevation it looks like (B)
As with all the solutions presented by the gurus I am sure this is really simple however, it is alluding me at this moment in time.
Any help would be greatly appreciated.

Create your profile:

Position it properly on the Z axis:

Add a 90° "Screw" modifier and a "Weld" modifier afterwards if it has vertices exactly on the axis, therefore overlapping vertices.

This is brilliant, thank you so much. Would this be the same process if the end result was to bend the shape?

@Russ there's also a "Bend" modifier to bend a 3D shape.