setXYZW method
Sets the x, y, z and w components of the vector at the given index.
Implementation
BufferAttribute setXYZW(int index, num x, num y, num z, num w) {
index *= itemSize;
array[index + 0] = x;
array[index + 1] = y;
array[index + 2] = z;
array[index + 3] = w;
return this;
}