Fix: USD import: set active mesh color. #105925

Michael Kowalski · 2023-03-20T16:22:03+01:00

Michael Kowalski commented

2023-03-20 16:22:03 +01:00

NOTE: this is a fix to regression in 3.5, so hopefully
it can be merged into the 3.5 release branch.

Fixed a bug where the active color wasn't being set
on imported meshes, resulting in no colors displaying
in the viewport.

This bug has been in the code for a long time. However,
the colors have been displaying correctly until recently,
so this issue wasn't previously apparent.

Also, changed custom color data name from "displayColors"
to "displayColor", to match the actual USD primvar name.
(This was a typo in the original code.)

Note that pull request

#104542

addresses other issues in the color import code (e.g.,
converting all color primvars and not just "displayColor",
avoiding hard-coding of attribute names, handling all
iterpolation types, etc.).

However, the current commit is meant as a short term fix
to a regression, where the "displayColor" attribute does
not render in the viewport at all, until the above pull
can be merged.

To reproduce the issue, import the pixar Kitchen_set.usd

https://openusd.org/release/dl_kitchen_set.html

with Color Attributes enabled. The meshes render black
when displaying color attributes is enabled in the viewport.
(Note that the kitchen set USD has only color attributes
but no actual materials.)

NOTE: this is a fix to regression in 3.5, so hopefully it can be merged into the 3.5 release branch. Fixed a bug where the active color wasn't being set on imported meshes, resulting in no colors displaying in the viewport. This bug has been in the code for a long time. However, the colors have been displaying correctly until recently, so this issue wasn't previously apparent. Also, changed custom color data name from "displayColors" to "displayColor", to match the actual USD primvar name. (This was a typo in the original code.) Note that pull request https://projects.blender.org/blender/blender/pulls/104542 addresses other issues in the color import code (e.g., converting all color primvars and not just "displayColor", avoiding hard-coding of attribute names, handling all iterpolation types, etc.). However, the current commit is meant as a short term fix to a regression, where the "displayColor" attribute does not render in the viewport at all, until the above pull can be merged. To reproduce the issue, import the pixar Kitchen_set.usd https://openusd.org/release/dl_kitchen_set.html with Color Attributes enabled. The meshes render black when displaying color attributes is enabled in the viewport. (Note that the kitchen set USD has only color attributes but no actual materials.)

Michael Kowalski added the

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Fix: USD import: set active mesh color. #105925