pS = THREE.RepeatWrapping
          grass.wrapT = THREE.RepeatWrapping
          grass.repeat.set(4, 4)

          // height map from http://danni-three.blogspot.com/2013/09/threejs-heightmaps.html
          this.third.load.texture('/assets/heightmap/heightmap-simple.png').then(heightmap => {
            const mesh = this.third.heightMap.add(heightmap)
            if (mesh) {
              // add custom material or a texture
              mesh.material = new THREE.MeshPhongMaterial({ map: grass })

        