diff --git a/doc/XMLreference.rst b/doc/XMLreference.rst index 28d97205..8c4b9431 100644 --- a/doc/XMLreference.rst +++ b/doc/XMLreference.rst @@ -2161,10 +2161,11 @@ rotations as unit quaternions. :at:`ref`: :at-val:`real, "0"` The reference position or angle of the joint. This attribute is only used for slide and hinge joints. It defines the - joint value corresponding to the initial model configuration. The amount of spatial transformation that the joint - applies at runtime equals the current joint value stored in mjData.qpos minus this reference value stored in - mjModel.qpos0. The meaning of these vectors was discussed in the :ref:`Stand-alone ` section in - the Overview chapter. + joint value corresponding to the initial model configuration. Note that the initial configuration itself is + unmodified, only the value of the joint at this configuration. The amount of spatial transformation that the joint + applies at runtime equals the current joint value stored in ``mjData.qpos`` minus this reference value stored in + ``mjModel.qpos0``. The meaning of these vectors is discussed in the :ref:`Kinematic tree ` section in the + Overview chapter. .. _body-joint-springref: