I have load an asset file in this format
<body name="robot0:hand mount" pos="1 1.25 0.15" euler="1.5708 0 3.14159">
<joint name="forearm_joint_x" type="slide" axis="1 0 0" damping="0.5" armature="0.005" limited="false"></joint>
<joint name="forearm_joint_y" type="slide" axis="0 1 0" damping="0.5" armature="0.005" limited="false"></joint>
<joint name="forearm_joint_z" type="slide" axis="0 0 1" damping="0.5" armature="0.005" limited="false"></joint>
<joint name="forearm_joint_roll" type="hinge" axis="1 0 0" damping="0.5" armature="0.005" limited="false"></joint>
<joint name="forearm_joint_pitch" type="hinge" axis="0 1 0" damping="0.5" armature="0.005" limited="false"></joint>
<joint name="forearm_joint_yaw" type="hinge" axis="0 0 1" damping="0.5" armature="0.005" limited="false"></joint>
</body>
Strangely after load the file the joint_name = “forearm_joint_y” disappeared. Then I modify the code as:
<joint name="forearm_joint_y" type="slide" axis="0 1 0" damping="0.5" armature="0.005" limited="false"></joint>
<joint name="forearm_joint_yaxis" type="slide" axis="0 1 0" damping="0.5" armature="0.005" limited="false"></joint>
<joint name="forearm_joint_z" type="slide" axis="0 0 1" damping="0.5" armature="0.005" limited="false"></joint>
This joint has showed but in strange position, in general they should list like [x,y,z,roll,pitch,yaw] in qpos of rigid_body, however they change the order as [x,y,roll,pitch,yaw,z]. I think maybe there is a bug in gym.load_asset() like cannot have more than 5 joint in a body? or it will re-order the dof list? Hope you can help me, thanks!