InstancedMesh: why fully refreshBoundingInfo even without bones

[kzhsw]

In this code, a forced refresh of bounding info is called in the constructor, which can cause performance issue when creating a lot of instances, since it requires to iterate through all vertices.

packages/dev/core/src/Meshes/instancedMesh.ts

A quick blame shows this belong to a skeleton-related fix

Blaming Babylon.js/packages/dev/core/src/Meshes/instancedMesh.ts at...

But in case bone or morph target does not exist on source mesh, there should be a much faster approuch.

   if (no bones and no morph targets) {
        let bi = this.sourceMesh.getBoundingInfo();
        this.buildBoundingInfo(bi.minimum, bi.maximum);
    } else {
        this.refreshBoundingInfo(true, true);
    }

Also link a similar question here:

refreshBoundingInfo called every time an InstancedMesh is created, even if not needed

We create and destroy instances all the time with high frequency (hundreds of avatars moving in and out of high fidelity ranges, and so on), and the InstancedMesh we use for this have mesh.doNotSyncBoundingInfo = true and mesh.alwaysSelectAsActiveMesh = true, since anything else is too costly. Every time we create an InstancedMesh, in its constructor this.refreshBoundingInfo(true, true) is called ( Babylon.js/packages/dev/core/src/Meshes/instancedMesh.ts at aeec5b9613b6d15942860ae6aba11b6792900…

[Cedric]

cc @bghgary

[bghgary]

This optimization seems reasonable to me but let’s get @Deltakosh to weigh in.

[Deltakosh]

I see no problem with it!

[bghgary]

@kzhsw Do you want to submit a PR?

[kzhsw]

instancedMesh: optimize initialization performance