USD Import Fails To Import Normals And Hard Splits Faces #107696

New Issue

Cici · 2023-05-07T02:17:16+02:00

Cici commented

2023-05-07 02:17:16 +02:00

System Information
Operating system: Windows-10-10.0.19042-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 2070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 527.56

Blender Version
Broken: version: 3.5.0, branch: blender-v3.5-release, commit date: 2023-03-29 02:56, hash: 1be25cfff18b
Worked: Blender 3.0 (Sort-of)

USD import of normals is failing, and is splitting quads from each other (even though those quads are triangles?)
See included USD file from Portal RTX (all Portal-RTX USD files have this problem).
Importing via USD with Blender 3.1+ will yield no normals and split faces. Opening with Nvidia's USD viewer shows the normals as intended.

Importing with Blender 3.0 will yield normals, however they are incredibly fragile. Entering edit mode will reveal they are "fake" and will turn to the flat shaded look again (as the faces are still split).
Attempting to transfer the normals to a flat version via a data-transfer modifier will break the normals as soon as the version with normals is selected as the target source.
Instancing the mesh data via geometry nodes (with an Object Info node) will not break the normals of the original object like the data transfer modifier does (however the output of the geom nodes modifier will still be flat shaded).

Saving the file and reloading keeps the normals, if loaded back into 3.0 (See included blend file). Loading into 3.1+ will break the normals again.

Adding and removing a custom split normals layer through the UI wont do anything. It neither saves nor disrupts the "Ghost Normals".

**System Information** Operating system: Windows-10-10.0.19042-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 2070/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 527.56 **Blender Version** Broken: version: 3.5.0, branch: blender-v3.5-release, commit date: 2023-03-29 02:56, hash: `1be25cfff18b` Worked: Blender 3.0 (Sort-of) USD import of normals is failing, and is splitting quads from each other (even though those quads are triangles?) See included USD file from Portal RTX (all Portal-RTX USD files have this problem). Importing via USD with Blender 3.1+ will yield no normals and split faces. Opening with Nvidia's USD viewer shows the normals as intended. Importing with Blender 3.0 will yield normals, however they are incredibly fragile. Entering edit mode will reveal they are "fake" and will turn to the flat shaded look again (as the faces are still split). Attempting to transfer the normals to a flat version via a data-transfer modifier will break the normals as soon as the version with normals is selected as the target source. Instancing the mesh data via geometry nodes (with an Object Info node) will not break the normals of the original object like the data transfer modifier does (however the output of the geom nodes modifier will still be flat shaded). Saving the file and reloading keeps the normals, if loaded back into 3.0 (See included blend file). Loading into 3.1+ will break the normals again. Adding and removing a custom split normals layer through the UI wont do anything. It neither saves nor disrupts the "Ghost Normals".

SK_Character_CameraBot_D_01.usd

940 KiB

camerausd WH.blend

5.1 MiB

Cici added the

labels 2023-05-07 02:17:17 +02:00