code: func Vec3Cross(dest, v1, v2 Vec3) {
  	dest[0] = v1[1]*v2[2] - v1[2]*v2[1]
  	dest[1] = v1[2]*v2[0] - v1[0]*v2[2]
  	dest[2] = v1[0]*v2[1] - v1[1]*v2[0]
  }
docs: // Vec3Cross derives the cross product of two vectors. dst = v1 x v2
  //
  //     dest   [out] The cross product.
  //     v1     [in]  A Vector.
  //     v2     [in]  A vector.