morph targets are not implemented

[kcoley]

Implement morph targets, which should help with https://github.com/kcoley/gltf2usd/issues/17

[donmccurdy]

I was under the impression USD(Z?) only supports keyframe and skeletal animation, not morph targets / blend shapes. Have you found docs or examples to suggest otherwise?

[kcoley]

@donmccurdy with their latest release before SIGGRAPH, they added support for skeletons and morph targets. Here is a link to some of their Doxygen documentation: https://graphics.pixar.com/usd/docs/api/_usd_skel__schemas.html#UsdSkel_BlendShape

[donmccurdy]

Awesome, thanks!

[enzyme69]

@kcoley Is blendshapes working already for USDZ?

[ox]

@enzyme69 I'm working on it in #16. If you want to see my progress, you can check out this branch.

[wave-electron]

@kcoley Blend Shapes has partial support now in USD v19.05. With some great help in the usd interest group I managed to get @ox morphedCube.usda test file working. I've attached the working usda file as zip.

In the original usda file these timecode below were wrongly set to 0

endTimeCode =  101
startTimeCode =1

and rel skel: animationSource = was added to the correct location below.

def Skeleton "skel"
            {

               rel skel:animationSource = <anim>

                def SkelAnimation "anim"

to run the usda file in usdview use command line:

usdview morphedCube.usda

There is also another problem on the MacOS installed of v19.05

to get the morphed targets rendering in the viewer

you need to open the interpreter and enter the following:

from pxr import UsdSkel UsdSkel.BakeSkinning(usdviewApi.stage.Traverse())

you also need to make sure you've pushed "play" on the animation

morphedCube.usda.zip

[wave-electron]

@kcoley I've attached what the current version of gltf2usd produces with the same archive animatedMorphCube.gltf usda attached below as zip file.

Apart from the issues I posted above. It is also missing the blendShapeWeights.timeSamples data for some reason?

float[] blendShapeWeights.timeSamples = {
                        0: [0, 0],
                        1: [0.00128, 0],
                         .....
                         100: [0, 0.00506],
                        101: [0, 0],

Current_animatedMorphCube.usda.zip