Shading is broken with Custom Normals + Triangulate Modifier #104244

New Issue

Guillermo Ojea Quintana · 2023-01-31T03:27:25+01:00

2023-01-31 03:27:25 +01:00

System Information
Operating system: Microsoft Windows 10 Professional (x64) Build 19045.2486
Graphics card: AMD Ryzen 5 3400G with Radeon Vega Graphics (AMD Radeon(TM) RX Vega 11 Graphics)

Blender Version
Broken: 3.3.2, bf24652e38, master, 2022-12-07, as found on the splash screen
Worked: None, as far as I know (Tested: 2.83.20, 2,93.14, 3.5.0-alpha as well)

Short description of error
As seen in the picture the shading is broken when there are custom normals and adding Triangulate Modifier

This is also broken when doing:

bm = bmesh.new()
bm.from_mesh(mesh)
bmesh.ops.triangulate(bm, faces=bm.faces)

I guess it is the same underlying code?

Exact steps for others to reproduce the error

Select default cube, enter Edit Mode, Mesh -> Normals (Alt-N) -> Rotate... and rotate the normals some degrees
Add Triangulate Modifier

What works: Instead of using Triangulate Modifier, using Face -> Triangulate Faces (Ctrl-T)

**System Information** Operating system: Microsoft Windows 10 Professional (x64) Build 19045.2486 Graphics card: AMD Ryzen 5 3400G with Radeon Vega Graphics (AMD Radeon(TM) RX Vega 11 Graphics) **Blender Version** Broken: 3.3.2, bf24652e38a2, master, 2022-12-07, as found on the splash screen Worked: None, as far as I know (Tested: 2.83.20, 2,93.14, 3.5.0-alpha as well) **Short description of error** As seen in the picture the shading is broken when there are custom normals and adding `Triangulate Modifier` ![broken-shading.png](https://archive.blender.org/developer/F14216249/broken-shading.png) This is also broken when doing: ``` bm = bmesh.new() bm.from_mesh(mesh) bmesh.ops.triangulate(bm, faces=bm.faces) ``` I guess it is the same underlying code? **Exact steps for others to reproduce the error** 1. Select default cube, enter `Edit Mode`, Mesh -> Normals (Alt-N) -> Rotate... and rotate the normals some degrees 2. Add `Triangulate Modifier` What works: Instead of using `Triangulate Modifier`, using Face -> Triangulate Faces (Ctrl-T)

Guillermo Ojea Quintana commented

2023-01-31 03:27:25 +01:00

Added subscriber: @alleysoft

Pratik Borhade commented

2023-01-31 05:46:30 +01:00

Changed status from 'Needs Triage' to: 'Confirmed'

Pratik Borhade commented

2023-01-31 05:46:37 +01:00

Added subscriber: @PratikPB2123

Philipp Oeser commented

2023-01-31 09:44:31 +01:00

Added subscriber: @lichtwerk

Philipp Oeser commented

2023-01-31 09:44:31 +01:00

The inconsistency in modeling tools regarding preserving custom normals has always been an issue, see these other reports:

#50604 (Knife Tool / Knife Project: Vertex group weights not added/interpolated for KnifeVerts created in faces (works correctly on verts created on existing/split edges))
#97698 (Custom Normals: some operations that alter topology (bisect, loopcut, subdivide, knife, triangulate modifier) destroy them while other operations (e.g. Connect Vertex Path, triangulate operator) preserve them)

I would think it is probably better to merge this with #97698 and update the report there to also include this case

The inconsistency in modeling tools regarding preserving custom normals has always been an issue, see these other reports: - #50604 (Knife Tool / Knife Project: Vertex group weights not added/interpolated for KnifeVerts created in faces (works correctly on verts created on existing/split edges)) - #97698 (Custom Normals: some operations that alter topology (bisect, loopcut, subdivide, knife, triangulate modifier) destroy them while other operations (e.g. Connect Vertex Path, triangulate operator) preserve them) I would think it is probably better to merge this with #97698 and update the report there to also include this case

Philipp Oeser commented

2023-01-31 09:47:21 +01:00

Closed as duplicate of #97698

Philipp Oeser closed this issue

2023-01-31 09:47:21 +01:00

Sign in to join this conversation.

No Label

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Shading is broken with Custom Normals + Triangulate Modifier #104244