Displacement From ZBrush to Arnold (Maya) gets twirly when animating facial rig

syoels

Hi Polycounters This is my ever message here after ghosting for a while and this place is the best. 

I'm an animation student, working on my first ever 3D short movie. 
I made a model, and I've recently added a facial rig which works fine (for a first timer). 
I wanted to move towards my next step which is adding a displacement map to roughen up the characters skin. 

I followed this workflow from Zbrush multimap exporter to Arnold for Maya, using these export settings: 


And connected them to my model using these hypershade & shape settings: 
 

All according to the guide I mentioned. 
Now, when the character is at it's default pose, it looks ok. Not perfect, but I am pleased enough with it.
Once I start animating it I am seeing pretty big warps all over the mesh, which seem (to my unprofessional eye) to be bigger then the vertices movement: 



Iv'e uploaded the scene and the Map tp this folder: https://drive.google.com/drive/folders/1L8wbK1zQ0xDanV3Wa0W_zNknFSHvGins?usp=sharing 
However I'm using a few plugins you might require to succesfully open the file with no errors (mGear, Braverabbit Shapes, ngSkinTools). 

I'd appreciate any feedback of any kind - 
but would most importantly like to know how to fix the strange warps on my dear whale's face when it moves  



Thanks a lot in advance! 

syoels

Just to further demonstrate my problem, Iv'e rendered out ~40 frames of my test scene and added the wireframe as an overlay:  

oglu

Apply a checker texture to the diffuse channel and take a look what does happen in the viewport and on the render. 

syoels

Good idea. 
Just from looking in the UV editor I noticed this behavior -
The UV set morphs during animation and overlaps itself + exceeds the UV defined square.
Is this expected? How can I fix this?

musashidan

check this thread:

https://simplymaya.com/forum/showthread.php?p=92761#post92761

As a sidenote, when exporting Disp maps from ZB set the subpix to 0. Having it at 4 does nothing and exponentially adds time to the bake. Some tutorials tell you to crank this up, but I tested it thoroughly and it has absolutely no effect on the quality of the map.

oglu

Looks like you animated the uvs. Maybe you where in uv mode and set a key? 

syoels

musashidan said:

check this thread:

https://simplymaya.com/forum/showthread.php?p=92761#post92761

This was it! The UVs were created after the blendshapes deforming while they should be done prior to any deformations/skinning. 
Since I couldn't drag the UV inputs via the inputs editor (it was undraggable) I simply unbound the skin and deleted the blendshapes node, and then re-imported them again (super easy if your'e using ngSkinTools for skinning & Braverabbit Shapes for blendshaping). 

I read it's also possible to somehow use the "mesh->transfer attributes" to transfer the UV's onto the model's intermediate shape (called shapeOrig or smth similar), didn't try it out, just putting it here as a pointer for people who might come across this thread. 

Thanks a lot !

Yerus

I wonder how did the Braverabbit Shapes aided you with? What does this plugin do?
PS: nice BS!!

syoels

@Yerus Thanks!
Shapes is actually a great plugin, it helps create & manage many of the different aspects of BS: https://vimeo.com/260911091 
(the video explains more than I know or use personally..)