StaticGeometryGenerator: Add support for InstancedMesh

[gkjohnson]

No description provided.

[timoisalive]

Hi!

Any news or plans on supporting InstancedMeshes?

And meanwhile, is there maybe an example somewhere how to use InstancedMeshes without the library support?

[gkjohnson]

This issue is about StaticGeometryGenerator. BVH already works with individual InstancedMesh instances.

[timoisalive]

This issue is about StaticGeometryGenerator. BVH already works with individual InstancedMesh instances.

Ok, sooo should I be able to create the collider without StaticGeometryGenerator?

I'm new to Three JS (and 3D in general), this is how I was able to generate the collider for my React Three Fiber group:

      new Octree().fromGraphNode(groupRef.current)

      const staticGenerator = new StaticGeometryGenerator(groupRef.current)
      staticGenerator.attributes = ['position']

      const mergedGeometry = staticGenerator.generate()
      mergedGeometry.boundsTree = new MeshBVH(mergedGeometry)

      const collider = new Mesh(mergedGeometry, new MeshBasicMaterial())

This doesn't however work with instancedMesh instances. Maybe I'm doing it all wrong...?

[gkjohnson]

Okay I see - yes it's correct that they are not supported with that function. You can manually convert the instanced mesh to one giant mesh but it is likely memory intensive. A separate top level acceleration structure would be best for handling something like instancing but that's not supported at the moment. If you'd like to try converting the instance mesh to a single geometry I recommend asking at the three.js forum.

[timoisalive]

Ok, thanks for the info! 🙏