Alembic don´t import vertex colors correctly
Closed, ResolvedPublic

Description

Hi!

Alembic don´t import vertex colors correctly

1- import Untitled_12.abc
2- Go to Vertex Paint Mode to see the vertex colors

Result: vertex colors are note the same as in the reference (check the attached image).
In Maya seems that the same file is imported OK.

Daniel

PS: I´m not sure but I think that the vertex color alfa channel is not imported ok too


Details

Type
Bug

Result looks like a mesh geometry interpolated from curves.
Problem looks like Blender is using on mesh vertices an index made for point control of curves.

Blender does not have vertex colors for Curves. But is it the case of application used to make original file ?
You did not precise how .abc file was made.

I think so, the application is called AnimVR.

Is it possible that the Alembic apply a kind conversion/transform between vertex colors for Curves to Meshes?, maybe how it is Maya alembic import does.

Looking the Image I've just realize it seems that the all vertex colors are squashed in the first vertices.

Daniel

Philipp Oeser (lichtwerk) triaged this task as Confirmed priority.Mon, Jan 8, 7:41 PM

I'm also getting Alembic: color index out of bounds reading face colors for object /Stage/Symbol/paint_1_1/Frames/FrameMesh, property Cd on import.
@Sybren A. Stüvel (sybren) : could you have a look?

We weren't using the provided index at all. As it turns out that index often just contains the indexed number, i.e. index[i] = i, so in those cases ignoring it was fine. I've implemented a lookup via that index now, and that fixed this issue.

Note that T53745 also suffers from Blender ignoring the index.