setDrawRange( start, count ) {

		this.drawRange.start = start;
		this.drawRange.count = count;

	}
Sets the draw range for this geometry.

@param {number} start - The first vertex for non-indexed geometry, otherwise the first triangle index.
@param {number} count - For non-indexed BufferGeometry, `count` is the number of vertices to render.
For indexed BufferGeometry, `count` is the number of indices to render.