hair rig bug for bendy bones

[Alessandro Padovani]

4.1.0.2168, blender 4.1

For bendy bones the hair rig is not added to the hair mesh, thus the hair doesn’t deform. Works fine for the other methods.

steps:

1. load G8F with toulouse hair
2. separate the hair and add a hair rig with the bendy bones option

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notes. These are not bugs but rather suggested improvements for usability.

1. add the hair rig to the figure collection
2. use stick as bone type rather than octahedral
3. reduce the size for the head bendy bone
4. make the bendy bones not selectable apart the handles
5. for bendy bones use 3 segments with curved vertex mapping
6. never hide bones and always separate the hair rig, these options are rather unnecessary

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[Alessandro Padovani]

note. better ik option.

The ik option isn’t much useful with a single target. We may add multiple targets similar to the bendy bones, but without stretch. A possible simple setup is to use multiple ik chains on the same bones chain. Test scene included multi-ik.blend.

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[Alessandro Padovani]

multiple ik targets

[Alessandro Padovani]

4.2.0.2218, blender 4.2 beta

popping. This is not fixed may have slipped. The bug is that the hair rig is not assigned to the hair. Other suggested improvements are optional of course. Or let me know if something is not clear.

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[Thomas Larsson]

You were right, I had missed this issue. The bug is now fixed. I haven’t thought about improvements, since I don’t make hair rigs myself anymore. I prefer hair curves for looks, but unfortunately is doesn’t seem to be a good way to pose them.

[Alessandro Padovani]

Commit 5c675cb, blender 4.2 beta

The bug is fixed thank you. Let me know if you want to look at the suggested improvements, otherwise I can close as resolved. The improvements above can be done by hand anyway.

As for posing hair curves, this is actually a limit with blender. Hair curves have a better and modern look but are difficult both to pose and simulate. Basically, the method to work with curves is to drive them with geometry using nodes. Thus we have a “geometry proxy hair“ driven by rigs or simulation, which in turn deforms the curves.

https://www.youtube.com/watch?v=VSwC5MHv5oI

[Thomas Larsson]

This was an interesting link. I have spent a few days implementing it in the Make Hair tool. It works well for Monica hair with the default settings, if you first separate the hair by material and build hairs from the four substantial meshes. It doesn’t work for Toulouse hair because it is not well designed; some sheets go from tip to tip with the root in the middle.

[Alessandro Padovani]

That’s great news, thank you for your work on this. Will give it a try tomorrow and let you know what I find.

[Alessandro Padovani]

4.2.0.2225, blender 4.2.0

bug. sparsity. When we use “sparsity” with “loose parts“ then the loose parts are generated but not deleted and we end up with a mess in the outline. Without “sparsity” it works fine.

steps:

1. generate hair with “loose parts“ and “sparsity“.

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update. Other than that the new simulation seems to work great so far. Will add notes if I find anything.

[Alessandro Padovani]

optimization. proxy hair parenting.

The proxy hairs can be parented to the head bone, instead of weightmapped to the head bone. This saves us the weightmaps for proxies which are always 100% to the head bone thus not needed and can be replaced with parenting.

This way the armature modifier for the proxies can be deleted as well.

[Alessandro Padovani]

possible bug. proxy rig with bendy bones.

I rigged the monica proxy hair with bendy bones and the rig acts strangely. That is, when I move a handle in the bendy bones some hair moves outside the supposed influence. This may be a bug in the weightmaps. Let me know.

steps:

1. prepare the monica hair so to have a scalp and a single hair mesh, I just used join as a last step
2. make hair with a single color so to get a single proxy, use “posing” + “line“ as proxy type
3. add hair rig to the proxy hair, with “bendy bones“ as rig type

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update. possible improvement. I found that the automatic weight improves a lot with some smoothing. Below an example with parameters. I believe the culprit is the joints where bones meet, in that area weights go wild.

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[Thomas Larsson]

The sparsity bug has been fixed.

[Alessandro Padovani]

Commit bf45a94 works fine thank you. See above for a possible improvement to weights.