Skin Influence Object Trouble

[diosalex]

Hi,
Well this is my problem:

Im using Maya 8.5 in WindowsXP,
Influence objects are curves with clusters on CV's
and the object is a Polygon model with nothing special.

I did a Skin bind, then added some curves as influence Objects, (in the skin node y turned on Components ), then I painted skin weights, at this point everything worked normal.

When I close the scene and open it again all the weights appear normal but the vertex moves just a little, as if the envelope was .2 instead of 1, maybe someone knows why this happens, I did the same procedure 3 times and works well but when I re-open the scene I get the same problem, I tried it all, painting weights again, I notice the weight values seem to be good , but the vertex moves too little, almost nothing

I would appreciate any help on why this happens,

Thanks.

[seith]

Again, please remember that in Maya 8.5 it is impossible to add an influence object to an existing skin cluster without getting into double transformation problems. It was a pretty huge bug that was fixed only in the SP1. Maya 2008 is fine though...

[joojaa]

QUOTE(seith @ 01/27/08, 06:42 AM) [snapback]280196[/snapback]
Again, please remember that in Maya 8.5 it is impossible to add an influence object to an existing skin cluster without getting into double transformation problems.

Its not impossible but its not how its supposed to work yes. But it can be cirumventted even without the sp1 one just needs to think out why it double transforms.

Anyway yes on maya 8.5 you relly need the sp1, 2008 has a bunch of other problems instead.

[seith]

QUOTE(Joojaa @ 01/27/08, 04:10 AM) [snapback]280208[/snapback]
Its not impossible but its not how its supposed to work yes. But it can be cirumventted even without the sp1 one just needs to think out why it double transforms.
Anyway yes on maya 8.5 you relly need the sp1, 2008 has a bunch of other problems instead.

Jooja, trust me, I tested the problem in four different Maya versions, and in the vanilla Maya 8.5 the "Use Components" flag on any skincluster is simply broken. So technically, adding influence objects works, as long as you don't need per-component deformation. If you do, you get a problem that looks like double transform and there's just no way around it. For information, the rig I tested worked fine in all the other Maya versions (from 6.0 to 8.0, then from 8.5 SP1 to 2008).

So I strongly agree with you and urge everyone to use the SP1 for 8.5, or 2008 which so far works splendidly for me. But I'm curious now, what kind of problems did you meet with 2008?

[joojaa]

QUOTE(seith @ 01/27/08, 10:57 PM) [snapback]280223[/snapback]
Jooja, trust me, I tested the problem in four different Maya versions, and in the vanilla Maya 8.5 the "Use Components" flag on any skincluster is simply broken.

I didnt dispute its state of brokenness. I just said even before sp1 you could circumvent the problem with a few extra utility nodes (which ends up re trasforming the opposite of the double, hence removing the double transform). Its not nice but can be done and took me some time to figure out. So im not in agreement about the NO WAY part of your comment, because your no way can in fact be done. *

Yes its a bug and its fixed (so no point in using the circumvention), however its not show stopping bug. A show stopping bug on the other hand is something you cannot even begin to fix because you have no such tool set.

*the same way leads to interesting hack where you don't need bones or proxy objects for your mesh deformations but can neatly just select regions of the deforming mesh as if they were the bones and they would deform when moved like the real deal despilte the fact that they lie in saparete part fo costruction history

[c000be]

for my WIP facial expressions, where i'm using wire influences for lip sync - onTheFly animation instead of blendshape because i have a full body character, so far i've found that parenting the wire to the appropriate joint before skinning, then applying the wire influence as the first in chain for the texture to be reacting to, is what worked for me.
this will also keep your wire moving appropriately with the rest of your model.

i have only done tests on rigs that have NOT been weight painted yet, and i will probably have to add some clusters above the lip, but i have found that it gives me a very nice subtlety that i don't think clusters would for a character that requires front of mouth, lip announciation.

here are the links to my post on cgtalk.com [you have to log in to see the jpg of the drawing of my rig] [url=http://forums.cgsociety.org/showthread.php?f=54&t=594934]baboon facial rig[/url]
there was a discussion about animating with vertices here: http://forums.cgsociety.org/showthread.php?f=26&t=595588

and here's my site basically, the pic of the final subDwireframe so you can see what i'll have to rig. the brow will also have a wire http://c000be.cgsociety.org/gallery/555991/ [and the other buttons in the 2nd row are for the basic models and tex's without lighting if anyone has an opinion]