I've setup a body rig for a character, skinned it and painted weights. I'm about to rig the face and begining to realize that its probably better to have the head  separate to the body mesh.

I've thought of a couple of ways I  though would work but they don't I was under the impression it would just be a case of:

- Export skin weight for full mesh
- Detach skin
- Separate head
- Duplicate exported skin weights file (head and body)
- Edit so there just the info need to each mesh respectively
- Bind each mesh to selected joints
- Import individual skin weights to the applicable mesh

Initially this seems to work .... that is until you move the rig and wierd things start to happen to the mesh.

I've also downloaded the Dora Skin Weight script and tried a few different options with this  but still no success.

Is there a way to actually do this. I don't want to lose the work I've already do with the weights?

Cheers

Wayne

i might be wrong here but i believe separating the mesh renumbers the vertices. which would cause the weighting to be off.

Iunderstand what your saying but I thought that when maya writes the weights to disk your get a file and image maps which seem to be based on UV layout. Come somebody confirm if this is the case?

Instead of exporting/importing the weights, I'd just keep a duplicate of the first mesh(still skinned), then bind the new mesh's to the same joints, and copy skin weights. Probably with "Closest point on surface" and "one to one".
-John

Any particular reason why you want the head to be separate?  Maya's weights tend to get screwed up really easily, and even the few plugins I've tried won't solve the issue.  If you're having a blendshape problem, there are a few scripts available that save only the vertices displaced which cuts the filesize down, if that's what you're looking for. 

As for UVs...it depends.  Yes, Maya does write weights to UV maps, and sometimes it works and sometimes it doesn't.  Ive had cases where the weights stick when I alter a model, and I've also had exploding deformations.  Make a copy, export the weights, detach the head, and do a test. 

>> I'm about to rig the face and begining to realize that its probably better to have the head  separate to the body mesh.


Why? It may actually come as supprise but having a separate head is jsut mroe work for the computer. Ergo slower.

But accurate, its only ever faster if you do not combine. So the operational word is combine. If you combine its allways slower to not combine becasue theres more operations in the chain. This said there is a slight possibility that if you have a lot of operations after the blend that operate on all points in the object. Now if thats the case you can rig the thing 2 times once for the proxy and once for not the datas freely transfeerable so its faster on all accords. Besides most likely the history is wrong anyway.

If you combine then you will allways be doing the combine which is slower than no combine. Since maya prunes the data to only those things that need to change it doesnt really matter if you have the rest with it or not.

It can be faster if you do not combine, however theres really no trick in haveing 2 chains that produce same things side by side for the separate had only sowing approach so its still not much idea to combine after the fact.

So no its not about how you combine. Combine is much heavier than a simple blend even IF it operated on all ponints wich is does not if you instruct maya to not operate on it.

In any case i digress thsi separete head and combine thing is one of those things why programmers get told not to prematurely optimize, somebody allready did it better than what you get by hand.

I'd like to know how to do this anyway - aside from speed, it might be handy to have the head not combined for some game engine scenarios (for example, where you might want to swap heads on the same body).

Doesent really matter you can do the head swap even if you only have one mesh in play. You just recreate the chain of events the same way. I think theres a mel animation i made somewhere that demonstrates the process. It doesnt even matter if the numbers get mixed up or not.

So instead of doing one body one had with blend merge, do many heads many bodies merge and blend that. (Its only more work if you ever do this manually its pretty easy to script)


THis all boils down to wether or not you want to invest in fast rig or not, the amout of work needed to be done for either is for most part exactly the same (hence i choose the fast rig over tha slow one given they cost as much to do).