I'm using a "box" to simulate a simple car as follows: <worldbody> <light directional="true" cutoff="100" exponent="1" diffuse="1 1 1" specular=".1 .1 .1" pos="0 0 1.3" dir="-0 0 -1.3"/> <geom name='floor' material="MatPlane" pos='0 0 0' size='40 40 40' type='plane' conaffinity='1' rgba='0.8 0.9 0.8 1' condim='3'/> <!-- Arm --> <body name="torso" pos="0 0 0"> <joint axis="0 0 1" name="rot" pos="0 0 0" type="hinge" range="-30 30" limited="true"/> <joint axis="1 0 0" name="slider" pos="0 0 0" type="slide"/> <geom fromto="0 0 0 0 0 0.2" size="0.25" type="cylinder"/> <geom pos=".15 0 0.25" size="0.1 0.1 0.05" type="box"/> </body> </worldbody> I expect that the orientation of the car is limited to range [-30, 30], and declare the above joint range. But the degree is always relative to the global axis. How can I limit the range of joint "rot" with respect to current orientation? Thanks a lot!