godotengine / godotengine/godot
Strange culling issue/ mesh appears inside out
- Dominant language
- C++
- Stars
- 117k
- Forks
- 26.8k
- PR merge metrics
- PR metrics pending
Description
### Tested versions
4.4 dev6
### System information
Godot v4.4.dev6 - Windows 10.0.22631 - Multi-window, 1 monitor - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 4060 (NVIDIA; 32.0.15.6614) - 12th Gen Intel(R) Core(TM) i5-12400F (12 threads)
### Issue description
I've been racking my brains regarding a strange face culling issue I'm having. I'm using a model that has asymmetrical parts and the meshes on one side display a culling issue, with the front faces being culled, despite the normals being set (and recalculated) correctly in Blender
the meshes that appear on the right appear correctly culled

but on the left side they're not

The modeler doesn't know what could be causing it but assumes it's a shader bug in Godot.
### Steps to reproduce
project attached with model displaying the behaviour. Normals have been checked in Blender
### Minimal reproduction project (MRP)
[culling_issue_project.zip](https://github.com/user-attachments/files/18049801/culling_issue_project.zip)
Contributor guide
Research direction
Start by opening the attached culling_issue_project.zip in Godot 4.4.dev6 and reproducing the asymmetrical mesh behavior described in the issue. Compare the correctly culled right-side meshes with the incorrectly culled left-side meshes, then verify whether the result is tied to the imported model, normals, or Godot's rendering path; done means the cause is identified and the culling behavior is corrected or clearly documented.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- blender, godot
- Domain
- computer-graphics, game-dev
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 30/100