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kcoley / gltf2usd

command-line utility for converting glTF 2.0 models to USD
MIT License
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Multiple Objects Rotating Animation Issue and PNG Transparency? #121

Closed enzyme69 closed 5 years ago

enzyme69 commented 5 years ago

santa_steve.zip

I have this 3 planes simply rotating in loop, I can see the GLTF animation looks correct, but when converted to USDZ, it's totally out of whack, wondering why...

And also is alpha transparency not yet supported with USDZ?

enzyme69 commented 5 years ago

It should look like this: leanflippantcob-max-1mb

enzyme69 commented 5 years ago

BLEND: AN_zoetrope_kaleidoscope_009_BAKED.blend.zip

kcoley commented 5 years ago

@enzyme69 looks like the glTF is using cubic spline animations, which are not supported in usdz. I haven't implemented a baking workaround for this yet in the tool. Is it possible to author the model with linear animations or bake the animations from Blender? That may work, though another issue you may hit is rendering planes in usdz, which might interfere with the shadow generation with ARQuicklook. You might need to make the planes into 3D meshes.

kcoley commented 5 years ago

@enzyme69 I haven't yet found a way to support vertex color alpha in usdz, since the python API expects vertex color to not have an alpha component.

enzyme69 commented 5 years ago

Thanks K, for explanation. I've been using multiple GLTF exporter, latest being the one from Blender 2.8 beta, but I think all of them are still WIP :D

kcoley commented 5 years ago

@enzyme69 closing for now