All instances of `MultiMeshInstance2D` are culled if the origin goes off screen

[markdibarry]

Tested versions

Reproducible in: 4.3.dev [9283d0d]
Not reproducible in: 4.3.dev [99fd6ca]

System information

Godot v4.3.dev.mono (9283d0d) - Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 3060 (NVIDIA; 31.0.15.4601) - AMD Ryzen 9 3900X 12-Core Processor (24 Threads)

Issue description

When the origin of a MultiMeshInstance2D goes off screen, all instances are culled.

According to clayjohn it may be the result of this PR: #79833

Before:

2024-02-17.12-25-51.mp4

After:

2024-02-17.12-27-05.mp4

Steps to reproduce

Run the MRP and move the camera off screen.

Minimal reproduction project (MRP)

MeshTest.zip

[markdibarry]

Found the problem area:

I think the odd part is that it only calls _multimesh_re_create_aabb() if multimesh->custom_aabb != AABB(), but the first thing in that method is:

So it should only call it if the condition is met, but also immediately return?

@puchik I'm not as familiar with this logic, so maybe you can weigh in?

[rburing]

In MeshStorage::_update_dirty_multimeshes (first screenshot) the condition to re-create the AABB should be when there is no custom AABB, that is multimesh->custom_aabb == AABB() (i.e. the opposite of the current condition).

[puchik]

@rburing is correct. This check was added immediately before pushing and was reversed by accident. I've made a PR that fixes this. Thanks for catching that!