code: function(matrix) {
      this.vertices = this.vertices.map(function(v) {
        return matrix.transformPoint(Vector.fromArray(v)).toArray();
      });
      if (this.normals) {
        var invTrans = matrix.inverse().transpose();
        this.normals = this.normals.map(function(n) {
          return invTrans.transformVector(Vector.fromArray(n)).unit().toArray();
        });
      }
      this.compile();
      return this;
    }
docs: ### .transform(matrix)  Transform all vertices by `matrix` and all normals by the inverse transpose of `matrix`.