code: func Vec3SAdd(dest, v1, v2 Vec3, s float32) {
  	dest[0] = v1[0] + v2[0]*s
  	dest[1] = v1[1] + v2[1]*s
  	dest[2] = v1[2] + v2[2]*s
  }
docs: // Vec3SAdd performs a scaled vector addition. dest = v1 + (v2 * s)
  //
  //     dest   [out] The result vector.
  //     v1     [in]  The base vector.
  //     v1     [in]  The vector to scale and add to v1.
  //     s      [in]  The amount to scale v2 by before adding to v1.