( function () { const _start = new THREE.Vector3(); const _end = new THREE.Vector3(); class Wireframe extends THREE.Mesh { constructor( geometry = new THREE.LineSegmentsGeometry(), material = new THREE.LineMaterial( { color: Math.random() * 0xffffff } ) ) { super( geometry, material ); this.type = 'Wireframe'; } // for backwards-compatability, but could be a method of THREE.LineSegmentsGeometry... computeLineDistances() { const geometry = this.geometry; const instanceStart = geometry.attributes.instanceStart; const instanceEnd = geometry.attributes.instanceEnd; const lineDistances = new Float32Array( 2 * instanceStart.count ); for ( let i = 0, j = 0, l = instanceStart.count; i < l; i ++, j += 2 ) { _start.fromBufferAttribute( instanceStart, i ); _end.fromBufferAttribute( instanceEnd, i ); lineDistances[ j ] = j === 0 ? 0 : lineDistances[ j - 1 ]; lineDistances[ j + 1 ] = lineDistances[ j ] + _start.distanceTo( _end ); } const instanceDistanceBuffer = new THREE.InstancedInterleavedBuffer( lineDistances, 2, 1 ); // d0, d1 geometry.setAttribute( 'instanceDistanceStart', new THREE.InterleavedBufferAttribute( instanceDistanceBuffer, 1, 0 ) ); // d0 geometry.setAttribute( 'instanceDistanceEnd', new THREE.InterleavedBufferAttribute( instanceDistanceBuffer, 1, 1 ) ); // d1 return this; } } Wireframe.prototype.isWireframe = true; THREE.Wireframe = Wireframe; } )();