Importing files with explicit normals (in this case from CAD data) discards (or recomputes) normals

[instinct-vfx]

Describe the bug
When importing geometry originating from CAD the included normals seem to be discarded and that creates very visual shading artifacts. If i import or load the same file in other DCCs this does not happen. It also does not happen when loading the file as a stage. But even if i duplicate the correct stage prim to a maya node the normals are discarded.

Expected behavior
Import normals properly, just like loading as a stage or other applications do.

Attachments
Find attached a comparison. The right side shows the exact same file loaded via the USD Layer editor as a stage. The left side shows the file imported via USD Import

Specs (if applicable):

• Windows
• Maya version 2023.3
• tested with Maya USD 0.26.0/0.27.0

[santosg87]

hi @instinct-vfx thank you for reporting this.

Are you able to share a sample file? this might be something within the maya side of things.
We know that there are some limitations to importing USD, since maya needs to convert and translate meshes into maya data when importing, but having a specific file might help us narrow down what could be causing the issue.