Blendshapes deforming wrong

[hman]

Hey everyone,

I'm having problems with my blendshapes. I created
blendshape for my character in its neutral pose.
I import that character into a scene and then
pose the character for animation. When I
slide the blendshape I created, a mouth wide open,
as an example. The mouth gets all distorted, and
looks nothing like the wide open mouth I created
for the character in its neutral pose.

Another thing I'm curious about is the best way
to create eye movements for my character, such
as the pupils moving from side to side. My
character's eyes are not a sphere but more
oval shaped. Should I use replacement eyes
and blendshape between them?

Can some offer solutions to this problem I'm having
with blendshapes?

-thanks!
hman
hassonp@hotmail.com

[carl-g-]

Hi, Sorry, but let me ask the dumb question first, did the morph work before exporting?

Since you've probably exported the model that you had tested and found worked fine, the next question is, were there any oddity's before you exported?

I've been running into a differnt sort of problem, ..but my thought's about the problem you have after importing is to ask about the option's you chose when you exported the character?

Did you set it to include history etc.? My own experience is that those Lattice's that were used in creating the morph target's are a blessing and a curse. The first head I did, gave me all these lattice's from Hell, and I couldn't close the scene without crashing out of Maya to the desktop, the morph's worked great though.

I suppose if you open the hypergraph and they aren't there after importing that's the part of the problem.

If all the history, and Lattice's came in then the most I can offer is, perhap's the order of deformation, (in what order the geometry deformation occurs) will end up being the problem,

If you look in the Forum, the other Blend Shape and Movement Question is mine, and the responce I got, pointed me toward this solution...I haven't gotten it to change the order it deform's retroactivly though.

When I did the Blendshape's, in the box I chose advanced/front of chain, as per my then instructer's advice, however a friend I have asked for advice in the past offered that in his own morphing , he chose advanced/before. To be fair though he was working from memory, and perhap's meant to say Front of chain.

Beyond offering that, good luck, if you get it figured out, I'd like to hear the solution.

[nieder3d]

-You could be experiencing deformation order problems, what you need to do is go back to the original character scene and move it away from the bind position, say translate your character root 10 or so in any direction , then try you blend shape, if you have distirtion here you deform order is wrong. Usually when you create blend shapes even if the deformation is wrong when you do it as long as you are at the bind pose it will look and act correct when your not it freaks out meaning your deform order is wrong and this is simple to correct. All you have to do is right mouse click over the bound head and go to Inputs>Complete List - a list will appear showing you all the deformable nodes on the surface, joint Clustor / Tweak / Blend Shape, etc, also at the very bottom you will see the shape node, what you want to do is move all your Blend Shape Nodes so they sit directly one after the other above the shape or make node, you can do this by Middle Mouse draging them. (whatever other nodes are in your deformation list should remain in there order above the blend shape nodes) Note:if you have patches you will have to do this with all the blend effected patches as well. This is caused when you create your blend shapes after you bind. If you create your blends shapes before you bind this is not a problem. I usually don't do my blends till it's time to lip sync and have to do the same process.
IF THAT IS NOT THE CASE- Then what you can do is delete your blend shapes, not the geometry just the blend nodes and save your seen out as Maya Asci format and then re-open your scene and redo your blend shapes and ajust there deformation order as above then save your scene out as first maya asci then maya .mb This is a work around when you have a blend F@%$ scene sometimes for no reason what so-ever, maya does weird things that you can't generally get to work with blend shapes, no matter what you do and I've scene people have to start over with starting fom older versions of there file, This happened to me and nothing worked and just before I was goping to try to trace the problem back through all my files up till I decided to delete the blend shape history save it as asci and re-open it and applied the blends- worked quite well after that- I got the Idea from Maya Live version 1 because most of the time when you saved out a camera after tracking video footage or something the camera would cause crazy problems with the scene like crashing for no reason, not rendering correctly etc. but I read somewheres if you save the camera as maya asci it would eliminate those problems, and it did...

-If this wasn't your case at all I would be interested in knowing what the problem was and if you ever got it to work.
-sid
sidgraphic@yahoo.com

[darby]

I agree that it is probably your defomation order causing the problem. As far as the eye animation technique... I have always found that using a texture map for the iris and pupil works the best. You just animate the UV translation/rotation nodes on the place2dtexture node of the shader to make them move... a really cool method is to create a cube in space that is linked to the root of your skeleton (so it moves with your character) and use set driven key to have the cube's rotation control the rotation of the texture map around the eyeballs. You can have the rotation channels of the cube control each of the texture maps in the same way so that they move together just as human eyes do (unless you go crosseyed =) and you can even set up a separate control to move the maps on each eye individually if you want to go crosseyed. As far as the eyelids though, you pretty much have to use blendshapes of your head geometry unless you want them to look really cartoony. Hope this helps!

[tjgalda]

eyeballs of feature film quality with whacked out shapes:

create a sphere for your eyeball
give it a point constraint to a locator so you can move your locator and the eyeball will watch it

model the shape of the eye using a lattice
parent the lattice and eyeball to the bone closest to them

that's it. simple, hey? the trick is that the lattice will consistently deform the sphere to the desired shape no matter what direction it faces in. now you don't have to worry about floating discs or geo for the pupil and all that garbage, or doing bleds, or any other nonsense.

Cheers,

TJ
--

TJ Galda
Technical Director
The Animation Group Ltd.

[stormtroopar]

give it a point constraint to a locator so you can move your locator and the eyeball will watch it

Do you actually mean an aim constraint?

[tjgalda]

Sorry, yes, aim. If you need clearer instructions, check out the Learning Maya book. Good old salty had that technique used for him.

Cheers,

TJ
--

TJ Galda
Technical Director
The Animation Group Ltd.