Added disableSparseSamples

[tryptik]

The UsdUtilsSparseValueWriter seems to write duplicate values for some curves. This P/R adds a disableSparseSamples flag to the mayaUSDExport command. When true, the sparse sample writer is disabled for the export.

This issue has been observed in the animation data in UsdSkelAnimation prims - similar values on an XForm do not seem to yield the same result. The disabling of the sparse sampling was applied across the board as a precaution. The modified test case shows where the issue is found in the scale animation. The result of the sparse sample export can be seen in the figure below:

I am covered under the Apple CLA as John Hood.

[seando-adsk]

@dgovil / @tryptik - Dhruv there are 3 persons listed on the CLA that I have on file for Apple, but "John Hood" is not one of them.

[dgovil]

@seando-adsk apologies, I just updated our CLA and sent it over with the name changes on there.

[seando-adsk]

@dgovil Thanks I got it. We'll proceed with an internal discussion about these changes.

[santosd]

Hi @tryptik and @dgovil, I am wondering if we have a test scene that we can look at that shows the issue with the duplicate values when using the UsdUtilsSparseValueWriter. We are trying to see if this is a bug that would need fixed in the sparser instead. Once we have a test file, we can take a closer look on our end. Thank you.

[tryptik]

Hi, @santosd, I agree that the issue may be in the UsdUtilsSparseValueWriter. The test/lib/mayaUsd/fileio/testDisableSparseSamples.py file builds a sample scene that reveals the issue -is that sufficient?

[santosd]

Hi @tryptik sorry for the delay on this one. I ran what is in the script locally on my machine (the building of the scene and the export) and I was not able to reproduce the issue that you show in your screen capture.
I ran this:

import maya.cmds as cmds

cmds.file(f=1, new=1)

grp = cmds.createNode('transform', name='root')
pcube = cmds.polyCube()
cmds.parent(pcube[0], grp)
cmds.select( d=True )

cmds.select(grp)
joint_a = cmds.joint()
joint_a = cmds.joint( p=(0, 0, 0))
cmds.joint( p=(0, 4, 0))

cmds.skinCluster(joint_a, pcube[0], tsb=1, mi=1)

cmds.setKeyframe("joint2.sx", t=0.0, v=0.0)
cmds.setKeyframe("joint2.sx", t=100.0, v=1.0)
cmds.keyTangent("joint2.sx", wt=1)
cmds.keyTangent("joint2.sx", e=1, index=(0,), itt='linear', ott='linear')
cmds.keyTangent("joint2.sx", e=1, index=(1,), itt='auto', ott='auto')

psphere = cmds.polySphere()
cmds.setKeyframe(psphere[0]+".sx", t=0.0, v=0.0)
cmds.setKeyframe(psphere[0]+".sx", t=100.0, v=1.0)
cmds.keyTangent(psphere[0]+".sx", wt=1)
cmds.keyTangent(psphere[0]+".sx", e=1, index=(0,), itt='linear', ott='linear')
cmds.keyTangent(psphere[0]+".sx", e=1, index=(1,), itt='auto', ott='auto')

Then I ran this for export:

import maya.cmds as cmds
usd_file = "C:/Users/santosd/Documents/maya/projects/default/scenes/sparse.usda"
cmds.mayaUSDExport(
    selection=False,
    exportDisplayColor=True,
    materialsScopeName="Looks",
    mergeTransformAndShape=True,
    shadingMode="useRegistry",
    defaultMeshScheme="none",
    exportSkin="auto",
    exportSkels="auto",
    frameRange=[70, 99],
    file=usd_file
    )

I then tried importing the resulting file to check the animation curves, but I am not seeing the issue you see.

Let me know if I am missing something.

Thank you.

[tryptik]

Hi, @santosd, sorry it took me a bit to get to this. If you re-import that Usd into Maya, you should see:

I used mayaUSDImport -f "[path-to-file].usda" -ani 1

[santosd]

Thank you @tryptik I am seeing the issue. I will work with @seando-adsk to look further into the issue and see if we can fix this on the sparser end.