4.0: using CharacterBody3D with collisions from "Single convex collision sibling" of a capsule mesh causes horrible performance

[atirut-w]

Godot version

v4.0.beta1.official [20d6672]

System information

Arch Linux

Issue description

Using Simplified or Multiple works fine, but Single is just straight chaos. It takes seconds for the splash screen to disappear and even then the performance is in the seconds-per-frame range.

Steps to reproduce

1. Set up a scene with a simple floor with trimesh static body
2. Create a CharacterBody3D and put the template script on it for the sake of simplicity
3. Put a capsule mesh on the character and create single convex collision sibling
4. Start the scene

Minimal reproduction project

CharacterBody3D Problem.zip

[Calinou]

Duplicate of #48587 (same cause). Use primitive collision shapes like CollisionShape3D + CapsuleShape instead.