XML Error: Schema violation: unrecognized attribute: 'passive' #2972
Description
Intro
Hi!
I am a graduate student at Indiana University. I'm part of Building A Mind Lab where we want to use MuJoCo in digital twin experiments within our origins of intelligence research program. We think MuJoCo will help us simulate biomechanical over actuated bodies with custom brain architectures within Unity via the Unity plugin. Thus far, everything has looked great, and I wanted to take a moment and thank you for all the great work.
My setup
MuJoCo: 3.4.0
Unity Plugin: 3.4.0
Unity: 6.0000.2.8f1
OS: macOS Sequoia 15.7.1
What's happening? What did you expect?
On loading any XML file with the latest (matched) MuJoCo and Unity Plugin versions, the XML error XML Error: Schema violation: unrecognized attribute: 'passive' is raised following which the simulation fails with NullReferenceException: Failed to create Mujoco runtime.
Although I tested with just two XML files (Ostrich and Ant) I imagine this would occur with any XML file since versions 3.3.6 and above replaces the passive flag with spring and damper flags within options but MjcfImporter.cs still appends passive along with the other default global flags.
Just commenting out L124 in MjGlobalSettings.cs solves the issue for me. But just in case, I also added the correct Spring and Damper flags to MjGlobalSettings.cs as and where needed. Everything seems to be running fine, but please let me know if more changes need to be made. I just wanted to report my patch incase useful.
Also, there is a minor mismatch in XML documentation, here it says damping but it should be damper instead I think.
Steps for reproduction
- Install the latest versions of mujoco and the Unity Plugin as per the documentation.
- Import any valid XML file.
- Run the simulation, and it should error out as described.
Minimal model for reproduction
If you encountered the issue in a complex model, please simplify it as much as possible (while still reproducing the issue).
minimal XML
<mujoco model="ant">
<compiler angle="degree" coordinate="local" inertiafromgeom="true"/>
<option integrator="RK4" timestep="0.01"/>
<custom>
<numeric data="0.0 0.0 0.55 1.0 0.0 0.0 0.0 0.0 1.0 0.0 -1.0 0.0 -1.0 0.0 1.0" name="init_qpos"/>
</custom>
<default>
<joint armature="1" damping="1" limited="true"/>
<geom conaffinity="0" condim="3" density="5.0" friction="1 0.5 0.5" margin="0.01" rgba="0.8 0.6 0.4 1"/>
</default>
<asset>
<texture builtin="gradient" height="100" rgb1="1 1 1" rgb2="0 0 0" type="skybox" width="100"/>
<texture builtin="flat" height="1278" mark="cross" markrgb="1 1 1" name="texgeom" random="0.01" rgb1="0.8 0.6 0.4" rgb2="0.8 0.6 0.4" type="cube" width="127"/>
<texture builtin="checker" height="100" name="texplane" rgb1="0 0 0" rgb2="0.8 0.8 0.8" type="2d" width="100"/>
<material name="MatPlane" reflectance="0.5" shininess="1" specular="1" texrepeat="60 60" texture="texplane"/>
<material name="geom" texture="texgeom" texuniform="true"/>
</asset>
<worldbody>
<light cutoff="100" diffuse="1 1 1" dir="-0 0 -1.3" directional="true" exponent="1" pos="0 0 1.3" specular=".1 .1 .1"/>
<geom conaffinity="1" condim="3" material="MatPlane" name="floor" pos="0 0 0" rgba="0.8 0.9 0.8 1" size="40 40 40" type="plane"/>
<body name="torso" pos="0 0 0.75">
<camera name="track" mode="trackcom" pos="0 -3 0.3" xyaxes="1 0 0 0 0 1"/>
<geom name="torso_geom" pos="0 0 0" size="0.25" type="sphere"/>
<joint armature="0" damping="0" limited="false" margin="0.01" name="root" pos="0 0 0" type="free"/>
<body name="front_left_leg" pos="0 0 0">
<geom fromto="0.0 0.0 0.0 0.2 0.2 0.0" name="aux_1_geom" size="0.08" type="capsule"/>
<body name="aux_1" pos="0.2 0.2 0">
<joint axis="0 0 1" name="hip_1" pos="0.0 0.0 0.0" range="-30 30" type="hinge"/>
<geom fromto="0.0 0.0 0.0 0.2 0.2 0.0" name="left_leg_geom" size="0.08" type="capsule"/>
<body pos="0.2 0.2 0">
<joint axis="-1 1 0" name="ankle_1" pos="0.0 0.0 0.0" range="30 70" type="hinge"/>
<geom fromto="0.0 0.0 0.0 0.4 0.4 0.0" name="left_ankle_geom" size="0.08" type="capsule"/>
</body>
</body>
</body>
<body name="front_right_leg" pos="0 0 0">
<geom fromto="0.0 0.0 0.0 -0.2 0.2 0.0" name="aux_2_geom" size="0.08" type="capsule"/>
<body name="aux_2" pos="-0.2 0.2 0">
<joint axis="0 0 1" name="hip_2" pos="0.0 0.0 0.0" range="-30 30" type="hinge"/>
<geom fromto="0.0 0.0 0.0 -0.2 0.2 0.0" name="right_leg_geom" size="0.08" type="capsule"/>
<body pos="-0.2 0.2 0">
<joint axis="1 1 0" name="ankle_2" pos="0.0 0.0 0.0" range="-70 -30" type="hinge"/>
<geom fromto="0.0 0.0 0.0 -0.4 0.4 0.0" name="right_ankle_geom" size="0.08" type="capsule"/>
</body>
</body>
</body>
<body name="back_leg" pos="0 0 0">
<geom fromto="0.0 0.0 0.0 -0.2 -0.2 0.0" name="aux_3_geom" size="0.08" type="capsule"/>
<body name="aux_3" pos="-0.2 -0.2 0">
<joint axis="0 0 1" name="hip_3" pos="0.0 0.0 0.0" range="-30 30" type="hinge"/>
<geom fromto="0.0 0.0 0.0 -0.2 -0.2 0.0" name="back_leg_geom" size="0.08" type="capsule"/>
<body pos="-0.2 -0.2 0">
<joint axis="-1 1 0" name="ankle_3" pos="0.0 0.0 0.0" range="-70 -30" type="hinge"/>
<geom fromto="0.0 0.0 0.0 -0.4 -0.4 0.0" name="third_ankle_geom" size="0.08" type="capsule"/>
</body>
</body>
</body>
<body name="right_back_leg" pos="0 0 0">
<geom fromto="0.0 0.0 0.0 0.2 -0.2 0.0" name="aux_4_geom" size="0.08" type="capsule"/>
<body name="aux_4" pos="0.2 -0.2 0">
<joint axis="0 0 1" name="hip_4" pos="0.0 0.0 0.0" range="-30 30" type="hinge"/>
<geom fromto="0.0 0.0 0.0 0.2 -0.2 0.0" name="rightback_leg_geom" size="0.08" type="capsule"/>
<body pos="0.2 -0.2 0">
<joint axis="1 1 0" name="ankle_4" pos="0.0 0.0 0.0" range="30 70" type="hinge"/>
<geom fromto="0.0 0.0 0.0 0.4 -0.4 0.0" name="fourth_ankle_geom" size="0.08" type="capsule"/>
</body>
</body>
</body>
</body>
</worldbody>
<actuator>
<motor ctrllimited="true" ctrlrange="-1.0 1.0" joint="hip_4" gear="150"/>
<motor ctrllimited="true" ctrlrange="-1.0 1.0" joint="ankle_4" gear="150"/>
<motor ctrllimited="true" ctrlrange="-1.0 1.0" joint="hip_1" gear="150"/>
<motor ctrllimited="true" ctrlrange="-1.0 1.0" joint="ankle_1" gear="150"/>
<motor ctrllimited="true" ctrlrange="-1.0 1.0" joint="hip_2" gear="150"/>
<motor ctrllimited="true" ctrlrange="-1.0 1.0" joint="ankle_2" gear="150"/>
<motor ctrllimited="true" ctrlrange="-1.0 1.0" joint="hip_3" gear="150"/>
<motor ctrllimited="true" ctrlrange="-1.0 1.0" joint="ankle_3" gear="150"/>
</actuator>
</mujoco>
Code required for reproduction
No response
Confirmations
- I searched the latest documentation thoroughly before posting.
- I searched previous Issues and Discussions, I am certain this has not been raised before.