RADENG_API Vec3 RADENG_CALL Unproject(const Mat4 &mvp, const int viewport[4], const Vec3 &p) { Vec3 z( 2*(p[0]-viewport[0])/viewport[2]-1, 2*(viewport[3]-(p[1]-viewport[1]))/viewport[3]-1, p[2] ); return mvp.Inverted().Transform(z); }