setXY method
Sets the x and y components of the vector at the given index.
Implementation
BufferAttribute setXY(int index, double x, double y) {
  index *= itemSize;
  array[index + 0] = x;
  array[index + 1] = y;
  return this;
}Sets the x and y components of the vector at the given index.
BufferAttribute setXY(int index, double x, double y) {
  index *= itemSize;
  array[index + 0] = x;
  array[index + 1] = y;
  return this;
}