Geometry Nodes - Realize Instances looses original collection meshes' autosmooth normal data #107376

New Issue

Andres Stephens · 2023-04-26T17:29:19+02:00

Andres Stephens commented

2023-04-26 17:29:19 +02:00

System Information
Operating system: Windows-10-10.0.22621-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 4090/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 531.68

Blender Version
Broken: version: 3.5.1, branch: blender-v3.5-release, commit date: 2023-04-24 18:11, hash: e1ccd9d4a1d3
Worked: Blender 2.9.3

Short description of error

Issue

Right now when you reference a collection of objects with different normal settings (smooth/autosmooth/no smooth and custom split normals) and then realize instances to later apply them for export - you can't without loosing or resetting the normal data to a new autosmooth setting.

Adding sharp edge splits in the original meshes in the collection doesn't 100% preserve the face normals, as the new autosmoothed normals on faces are re-calculated differently on the new GN mesh

Exact steps for others to reproduce the error

Desired UX

Realize the instances of a collection
Preserve the normals set per object in the collection on the GN object
Apply GN tree on export for single meshes in FBX or other workflows, or for asset libraries that are much more performant in layout - with original applied normals.

In blend file attached:

mute the Realize Instances node to see how the normals of the green monkeys change their normals.

User Story:
This is useful for a user when they need to have an editable yet final object with applied normals and such made of multuple objects, but the project requirements requires minimal mesh data manipulation and instancing - ei.. 10 objects making a prop, but one prop mesh as single mesh data both for memory management and minimal scene management. Their art director needs to change the prop handle, this file needs to be exported again or saved as new linked data - single mesh. But the normals of all the sub-objects merged together need to be preserved - as this is a low poly asset designed for games and quick rendering in Eevee. This is impossible since now the FBX is exporting multiple meshes per collection, or the merging/marking sharp process has to be done manually over and over and over again - slowing down the pipeline and wearing the artist down.

Notes:

Seems normal attributes are no-longer a thing? Could this be the cause? (Blender 2.93)

**System Information** Operating system: Windows-10-10.0.22621-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 4090/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 531.68 **Blender Version** Broken: version: 3.5.1, branch: blender-v3.5-release, commit date: 2023-04-24 18:11, hash: `e1ccd9d4a1d3` Worked: Blender 2.9.3 **Short description of error** ## Issue ![blender_nAFs9oQiAa.png](/attachments/fc289af5-45de-4764-b021-908cf2505ac7) Right now when you reference a collection of objects with different normal settings (smooth/autosmooth/no smooth and custom split normals) and then realize instances to later apply them for export - you can't without loosing or resetting the normal data to a new autosmooth setting. ![blender_0vFIPVwBrG.gif](/attachments/d17934b6-e906-4e32-9923-39a00d359818) - Adding sharp edge splits in the original meshes in the collection doesn't 100% preserve the face normals, as the new autosmoothed normals on faces are re-calculated differently on the new GN mesh **Exact steps for others to reproduce the error** ## Desired UX 1. Realize the instances of a collection 2. Preserve the normals set per object in the collection on the GN object 3. Apply GN tree on export for single meshes in FBX or other workflows, or for asset libraries that are much more performant in layout - with original applied normals. In blend file attached: - mute the Realize Instances node to see how the normals of the green monkeys change their normals. **User Story:** This is useful for a user when they need to have an editable yet final object with applied normals and such made of multuple objects, but the project requirements requires minimal mesh data manipulation and instancing - ei.. 10 objects making a prop, but one prop mesh as single mesh data both for memory management and minimal scene management. Their art director needs to change the prop handle, this file needs to be exported again or saved as new linked data - single mesh. But the normals of all the sub-objects merged together need to be preserved - as this is a low poly asset designed for games and quick rendering in Eevee. This is impossible since now the FBX is exporting multiple meshes per collection, or the merging/marking sharp process has to be done manually over and over and over again - slowing down the pipeline and wearing the artist down. **Notes:** - Seems normal attributes are no-longer a thing? Could this be the cause? (Blender 2.93) ![blender_0vFIPVwBrG.gif](/attachments/d17934b6-e906-4e32-9923-39a00d359818)

Realizing Instances looses normals_01.blend

1.0 MiB

blender_zAWJE7IJ2O.png

12 KiB

blender_0vFIPVwBrG.gif

3.1 MiB

blender_nAFs9oQiAa.png

422 KiB