Will three.js Object3D.clone() create a deep copy of the geometry?

Question

I\'m loading models using the collada loader. The loader returns an Object3D, \"dae\", with many child meshes. I\'d like to instantiate the parent \"dae\" object many times

Answer 1

three.js Object3D.clone() will not create a deep copy of geometry and material. It will reference geometry and material of the cloned object instead.

You can see this in three.module.js:

Mesh.prototype = ... {

    ...,

    copy: function ( source ) {
        Object3D.prototype.copy.call( this, source );

        ...

>>>>>>> this.material = source.material; <<<<<<<
>>>>>>> this.geometry = source.geometry; <<<<<<<

        return this;

    }

    ...

}

So, regarding the OP's question: Yes, you can just use dae.clone().

For a deep clone including geometry and material, just change two lines of the above Mesh.prototype.copy() function:

this.material = source.material.clone();
this.geometry = source.geometry.clone();

Keep in mind this is a performance issue because three.js has to calculate separate geometries for each object3D, including all Meshes.