MultiMeshInstance3D performance

[scenic trellis]

I am testing out my chunking system. For testing purposes I am creating a grid of 256 chunks. each chunk is populated by 10 instances of a single multimesh. so, 2560 instances. and the mesh is low poly, its just a cylinder.

But I am getting a crazy drop in fps. meanwhile I can set that same mesh as my bullet mesh and spam it with no fps drop. obviously I dont understand how to use multimesh, but there doesnt seem to be any up to date documentation. I found a couple tutorials talking about it but they are all very basic.

edit for answer: the y axis on my normals was slightly off

[naive hamlet]

how many faces do the cylinders have?

2560 instances all in front of you are significant, specially when dealing with lighting and materials.

The editor always runs slower than an export, and without a strong PC that can be worsened.

MultiMeshInstance merely lets you draw several identical meshes with less resource usage and with the overhead of a single node. There is no real trick to it once you set the instances for it..