Hi @a519894574, welcome to the community!
Just to clarify, are those models loaded as a Cesium3DTileset? Or are these models that you are adding through Unreal’s mesh importer?
From a glance, it looks like the rays are passing through areas with really small triangles – perhaps even degenerate ones. Chaos (the physics engine) cannot always handle collisions with these small triangles. In the past, we found that applications could temporarily freeze when colliding with degenerate triangles in a tileset. That’s why when we generate physics meshes for tilesets, we intentionally prevent degenerate triangles from being added to physics meshes. If these triangles weren’t removed, you could experience freezes as well.
Also, I’m not sure if you’re using Nanite in your project, but we haven’t tested how well 3D Tilesets work with Nanite. That might be another complication.
What are your reasons for needing tileset collisions? For example, is it for character movement? For selecting objects with the mouse? We can try to find a workaround depending on your use case.