Unity Plugin: hfield support and ArgumentException when loading MJCF file

[xavier2933]

Intro

Hi!

I am a graduate student at CU Boulder, I use MuJoCo for my research on lunar rover simulations.

My setup

I am using:

Unity version: 6000.0.40f1

MuJoCo Unity Plugin version: 3.3.6

My question

I am attempting to use an hfield for terrain in a Unity simulation with the MuJoCo Unity plugin. When I load my MJCF XML file, I encounter the following error:

ArgumentException: Unsupported geom shape detected
Mujoco.MjMeshFilter.Update () (at ./Library/PackageCache/org.mujoco@42a834cb3c67/Runtime/Components/Shapes/MjMeshFilter.cs:72)

This error prevents the model from loading. I have confirmed that the same XML file works correctly in the native MuJoCo Simulate program.

My goal is to use a height field to create a complex, non-convex terrain with realistic valleys and holes. I need to avoid using a standard mesh () because MuJoCo's default interpretation of a mesh as a convex hull is unsuitable for my application.

The documentation for MuJoCo on readthedocs.io (https://mujoco.readthedocs.io/en/stable/unity.html) suggests that hfields are supported in the Unity integration, but this appears to be a discrepancy with the current public version of the plugin.

Is hfield functionality currently supported by the MuJoCo Unity plugin? If not, is there a planned release timeline for this feature, or a recommended workaround that allows for non-convex terrain collision?

Minimal model and/or code that explain my question

Here is the relevant portion of my XML file:

XML

<asset>
    <hfield name="pit" nrow="400" ncol="400" file="testpit_5cmpp_gray.png" size="14 10 2 0.1"/>
</asset>

<worldbody>
    <geom type="hfield" hfield="pit" rgba="0.5 0.35 0.2 1" friction="1 0.5 0.5"/>
</worldbody>

This file and mesh render properly in the mujoco simulate program.

Confirmations

• I searched the latest documentation thoroughly before posting.
• I searched previous Issues and Discussions, I am certain this has not been raised before.