An Invisible Error When Creating a MultiMesh

Godot Version

I am using the latest version of Godot 4.7.2.

Question

Hello, this is my first time posting on this forum. I’ve spent several hours trying to solve this problem with GPT, but I still haven’t been able to fix it, so I’m asking here. I used GPT to translate this into English, so please excuse any awkward wording.

  1. What I wanted to do

I simply wanted to create a box mesh using a MultiMeshInstance3D node.

  1. The problem

As shown in the image below, the MultiMesh does not appear at all.

There is one strange thing, though. If I adjust the Custom AABB values under the MultiMesh section in the Inspector, a strangely distorted box mesh appears, as shown below.

After that, changing the Custom AABB values again does not change the shape shown in the image.

Oddly enough, if I change Material → Albedo while it is in this state, the mesh becomes colorful.

Below is what happens when I set the Instance Count to 2.

In other words, when I create two box meshes, they appear like this.

Every time I increase the Instance Count, another one of those blade-like shapes is added.

- It’s hard to believe that such a simple but serious problem is happening only to me…

However, I couldn’t find anyone with the same issue even after searching the web.

I’m fairly new to Godot, so I suppose it’s quite possible that I’m doing something wrong. However, as far as I can tell, I’m following the correct procedure.

I also tested this with previous versions of Godot.

4.6.3 — Same behavior as 4.7.2, including the strange behavior when modifying Custom AABB.
4.5.2 — Same overall behavior, although the shape that appears when modifying Custom AABB is slightly different. In this version, it appears as a straight pillar.

GPT keeps telling me to run more tests. However, even after pasting and trying various scripts that GPT provided, the box mesh still does not appear.

I’m exhausted. I feel like Sisyphus at this point.

Does anyone have any idea what might be causing this?

For reference, I am using an RTX 4070 and 16 GB of RAM.

Nothing shows because MultiMeshInstance3D is an optimized node to render the same mesh hundred or thousands of times and it’s expected to be populated with a script using its API.

You can also populate it in the editor by scattering the instances onto another mesh:

If you only want to show a mesh use a MeshInstance3D

Thank you! The issue has been resolved. I was able to use the “Populate Surface” method, which allowed me to achieve the look I wanted. The suggestion was also very helpful. Have a great day!