I need it for demo purposes, so performance is no very important for now. No textures are used for simplicity sake. It will be ok, for example, reload all mesh or just hide some of triangles (for example, I would like to remove all triangles, containing single random vertex). Also, is it possible to split source object to some pieces?

How is it possible to edit mesh (runtime or not)?
Void Object3D.addTriangle exists, but no delete/remove triangle found.