_reindexFaces() {

		const activeFaces = [];

		for ( let i = 0; i < this.faces.length; i ++ ) {

			const face = this.faces[ i ];

			if ( face.mark === Visible ) {

				activeFaces.push( face );

			}

		}

		this.faces = activeFaces;

		return this;

	}
Removes inactive (e.g. deleted) faces from the internal face list.

@private
@return {ConvexHull} A reference to this convex hull.