 {
        let boxBuilder = new BoxBuilder();
        boxBuilder.pushCube([0, 0, 0], floorSize);
        let boxPrimitive = boxBuilder.finishPrimitive(renderer);

        let boxMaterial = new PbrMaterial();
        boxMaterial.baseColorFactor.value = [0.3, 0.3, 0.3, 1.0];
        let boxRenderPrimitive = renderer.createRenderPrimitive(boxPrimitive, boxMaterial);

        floorNode = new Node();
        floorNode.addRenderPrimitive(boxRenderPrimitive);
        floorNode.selectable = true;
        scene.addN