Transferring Vertex Groups (Hair Particle System workflow)

lilweep

Goal

I made a particle system hair on one Diffeomorphic-imported figure and I want to use it on another Diffeomorphic-imported figure.

Problem

I have not had much success transferring the particle system hair across to different figures.

The actual Particle System itself (i.e., the style curve particles) can be transferred over easily enough by copying modifiers, but the corresponding Vertex Groups that define the hair density do not transfer properly from one mesh to another.   So only the particle strands show but none of the children strands show.

When I attempt to transfer the Vertex Groups by transferring mesh data (either by using Ctrl+L or ortherwise by using a Transfer Mesh modifier), the results are always the same.  The Vertex Group gets distorted as per pictures below.

Attached images

• 1 = the vertex group i want to transfer
• 2 = the result of using the transfer mesh modifier shown in 3

lilweep

I assume someone else has already worked out a functioning workflow for using Particle System hair and transferring between different meshes, so might help if someone outined that for me here, since that is my endgoal anyway.

I already attempted a workaround.  Instead of using Vertex Groups, I'm trying Textures to drive the density and clumping and this approach is only somewhat functional.

One of the problems is that it stops the Cycles render in viewport for some reason (and no I dont have pause preview render clicked). 

In general Texture painting gives more finesse in describing the areas to grow hair but seems to be a lot laggier because I guess its culling the hair density after the fact rather than before?  I would much rather use Vertex Groups as the primary way to control the Density, and then maybe only use Texture to further refine it if needed.

lilweep

So y'all are really out here remaking your particle hair every time you want to use it on another character huh?

andya_b341b7c5f5

Have you tried the Copy Vertex Weight to Selected option in the Vertex Group Specials menu, or enabling the built-in Copy Attributes Menu add-on and using Ctrl-C?  Both work for me, with objects that are copies of one another so vertex number and order are identical.  I doubt it will work (well) by any method otherwise.

 

 

Krys Kryngle

Make your particle hair on a separate mesh and then wrap/parent that mesh to the character.  This is pretty common practice.  Many hair styles that you import will already have the hair attached to a separate mesh, often called the 'scalp' for head hair.  You can then import the 'scalp' mesh into another project and it will bring the particle system along.

Padone

If the figures are the same generation you don't need to transfer but just to copy because the vertex number and order will be the same.

lilweep

andya_b341b7c5f5 said:

Have you tried the Copy Vertex Weight to Selected option in the Vertex Group Specials menu, or enabling the built-in Copy Attributes Menu add-on and using Ctrl-C?  Both work for me, with objects that are copies of one another so vertex number and order are identical.  I doubt it will work (well) by any method otherwise.

hmm tried both and neither worked:

• Copying the Vertex Weight to Selected on Vertex Groups Specials menu
• Copying using copy attributes add-on

Maybe the topology hasnt been preserved

Padone said:

If the figures are the same generation you don't need to transfer but just to copy because the vertex number and order will be the same.

Does merging geografts maintain vertex order (assuming the two figures are same generation and geografts are the same)?

Padone

@lilweep May be I don't know, but you better copy the maps before merging the geografts, or editing the geometry in any other way.

lilweep

Okay, I did some experiments and confirmed that merging geografts does not conserve vertex order.

Whatever happened to the Geometry Nodes option?

lilweep

Krys Kryngle said:

Make your particle hair on a separate mesh and then wrap/parent that mesh to the character. 

how do i do this, by the way? (the wrapping/parenting part)

Padone

@lilweep The geometry node option is there as always, though I wouldn't advise to use it in production since geometry nodes are experimental yet.

lilweep

Padone said:

@lilweep The geometry node option is there as always, though I wouldn't advise to use it in production since geometry nodes are experimental yet.

is it tho? (version 1.6)

Padone

You're probably using an old version of the plugin, you need to get the dev version for the new features.

lilweep

oh