I can remove the old mesh, and add a
new Mesh using the new geometry. Isn’t this just as costly (or more) as the old
setMaterial methods that there were before?
TLDR: Before you waste time reading further, it is easy to change the geometry or material of a Mesh (@mrdoob please confirm) :
// clean up the old geometry if you won't use it anymore mesh.geometry.dispose() mesh.geometry = new SomeGeometry(...) // clean up the old material if you won't use it anymore mesh.material.dispose() mesh.material = new MeshSomeMaterial(...)