value: function transformVector(matrix, vector) {
   var result = vec4.transformMat4([0, 0, 0, 0], vector, matrix);
   var scale = 1 / result[3];
   vec4.multiply(result, result, [scale, scale, scale, scale]);
   return result;
 }
 // TODO - replace with math.gl
 transformVector(matrix, vector) {
   const result = vec4.transformMat4([0, 0, 0, 0], vector, matrix);
   const scale = 1 / result[3];
   vec4.multiply(result, result, [scale, scale, scale, scale]);
   return result;
 }