I have one mesh for a complete character (dark gray) and a copy of the head area as another mesh (light gray).
The second mesh is the emitter for all of the hair (eyelashes, eyebrows, beard, ear hair, etc)
I need the second mesh to follow and deform exactly like the first.
If they don’t the beard, especially on the neck, will pop off or fall under the main mesh.
The second mesh has the same topology as the first.
Is there a way to weight the main mesh and then copy the weight painting to the matching vert’s in the second?
Am I using a wrong approach?
You could just use one mesh, make sure render emitter is set and use vertex groups ( Density ) for different areas… hair beard etc then have a particle system for each.
When using separate meshes for animated characters like this, it’s probably better to wait until the modeling, weighting and other animation-related steps are finalized, then duplicate the already-weighted mesh to add the hair particle systems. This insures exact weight matching without using such means as scripting, which can be problematic. Because the 2.5x API is only recently stabilized, I don’t think there are yet scripts for doing this sort of thing. I have one for 2.49b that I adapted from another script that had a different purpose, but it won’t work in 2.5x because of the API overhaul. You might ask/search on other Blender sites to see what’s up and coming for 2.57 scripts.
batFINGER,
Thanks for the reply. I have created a node system for SSS on the skin and would prefer to keep the hair separate for a bit of simplicity. Seems both solutions have their problems.
chipmasque,
You might ask/search on other Blender sites to see what’s up and coming for 2.57 scripts.
I’ll see what I can find out there.
If all else fails, I guess I will have to duplicate the mesh and recreate the emitters after the weight painting is complete.
I think I will need to rig the entire face before duplicating the mesh for the hair.
This seems rather inflexible. I mean, if I chose to add a bone to the face some time down the road, I will have to delete the hair and start over again correct? I would think there is a better way but I’m just learning this part.
Are there any other traps I should be aware of before duplicating the mesh? Will shape keys and rigging, all work?
It’s really only inflexible if you want to have duplicate deforming meshes and they need to match exactly in their deformations. The other option is to match the weights vertex by vertex, tedious but maybe not as much as redoing the hair systems. A script should work fine if it’s well-written, I had good results from the one I used in earlier versions, but developing a good one takes time just as any other task will.
Also keep in mind that you really only need to match weights for portions of the mesh that actually deform. For “wigs” I usually just dupe the skullcap of the character (usually rigid) and add a hair system. If later on it doesn’t match the skull exactly it usually makes no difference, but that also depends on your character & the kind of hair it has. The same is true for some kinds of facial hair as well – sometimes a close match in the deformations is good enough.
So adding a bone may not be a huge issue if it doesn’t affect the particle emitter deformations, or affects them very little. However, editing the mesh is another matter. Very important: if you edit the emitter mesh in a way that changes the topology (such as adding or removing vertices, faces, or edges), it can severely disrupt the placement of particle hair stands. Sometimes you can remove an entire loop with no effect. But in most cases these kinds of edits do bad things to particle strand placement. So it’s better to have your models & rigging nailed before adding particle hair systems.