abc to usdz - textures are scrambled

Hi there!


I was successfully able to convert .obj to .usdz with all the texture maps applied.

When I do the same with a .abc file the textures are all scrambled - it appears to be an issue with the uv's.

I'm using Maya and Substance Painter and xcrun.

Any help will be much appreciated!


Thanks!

Replies

Can you explain the OBJ to USDZ with all the texture maps applied? Are you using Blender or Maya?


I am curious also with ABC and scrambled texture.

I tried the following process with both Blender and Maya. I'm also running a React app locally so I Quick Look the cube through Safari.


A. OBJ to usdz:

1. Create a cube

2. Unwrap the uv's

3. Export OBJ

4. Paint and export PBR textures from Substance Painter

5. Convert to usdz with usdz_converter and apply only the color map:

xcrun usdz_converter cube.obj cube.usdz -g pCube1 -color_map cube_BaseColor.png -v


B. ABC to usdz:

1,2 same as above.

3. Export Alembic (ABC) and FBX (for Substance Painter)

5,6 same as above.


OBJ -> usdz textures are applied correctly, i.e. each cube face is a different color. ABC to usdz appears scrambled, i.e. the color map is applied but the scale and location is weird.


Upon inspecting the file in Xcode/SceneKit, it seems that upon converting ABC to usdz the texture coordinates are lost. They're definitely there in the Alembic file- could this be a bug?


Does that clarify my process? Any thoughts or solutions?

My workflow is using Blenders Alembic exporter. The animations and geometry seem to be working as expected, but I’ve also found materials are scrambled for abc. Using obj my usdz files come out fine, and the PBR materials apply correctly.


You can generate the usda file by using -l -d option for the following command line (i’m only including color_map for simplicity)


# xcrun usd_converter -l -d file.abc -g mesh1 file.usdz -color_map basecolor.png -v


or for obj


# xcrun usd_converter -l -d file.obj -g mesh1 file.usdz -color_map basecolor.png -v



I found that both the obj & abc created usda ascii files have the same material:binding, however, the materials are working for obj but scrambled in abc


I’m thinking maybe a bug as well... But surely Apple wouldn’t release this without checking the materials are working?