Building

Warning

OpenUSD support is currently experimental and subject to frequent change.

Advanced users can start testing out USD support by building against their own USD libraries or USD built from source.

This assumes that you have built MuJoCo in ~/mujoco and have a build directory at ~/mujoco/build

Building USD

USD has a pretty streamlined installation via their build_usd.py script. It’s recommended to use a separate installation directory that exists outside of the cloned repository directory.

git clone https://github.com/PixarAnimationStudios/OpenUSD
python OpenUSD/build_scripts/build_usd.py /path/to/my_usd_install_dir

Enabling USD

USD is comprised of many plugins. When USD enabled application starts up it looks for an environment variable called PXR_PLUGINPATH_NAME. Below is an example where we build MuJoCo with USD enabled and set this variable.

cd ~/mujoco/build
cmake .. -DCMAKE_BUILD_TYPE=Release -DUSD_DIR=/path/to/my_usd_install_dir
cmake --build . -j 30; sudo cmake --install .
export PXR_PLUGINPATH_NAME=/usr/local/lib/mujocoUsd/resources/*/plugInfo.json

If we now run simulate.cc, we will be able to drag and drop USD files.

simulate

Enabling plugins in Houdini

Houdini is a procedural content authoring tool with extensive support for USD workflows via their Solaris context. It’s highly popular in the VFX industry, and it’s easy to imagine procedural generation tools for simulation ready assets and scenes.

To allow support for loading MJCF files in Solaris, and usage of the mjcPhysics schemas you can build against Houdini’s USD libraries. To do so, simply run source ./houdini_setup as descrived in the SideFX documentation.

cd ~/mujoco/build
cmake .. -DCMAKE_BUILD_TYPE=Release -DHOUDINI_HFS_DIR=$HFS
cmake --build . -j 30; sudo cmake --install .
export PXR_PLUGINPATH_NAME=/usr/local/lib/mujocoUsd/resources/*/plugInfo.json
houdini