mitsuba2lxd

Launch an LXD container with Mitsuba2 inside

The following information is focused on the GPU script variant, since it is more complex to run. A CPU-only script is provided as well for reference.

Introduction

This script checks your LXD installation and launches a new Ubuntu Minimal 20.04 Focal Fossa container.

Inside of the container it installs all necessary packages including CUDA 10.2, so make sure to have a compatible GPU and drivers installed on the host machine.

This script is designed for Ubuntu/Debian. If you're interested to make it work in other distros, feel free to submit a pull request.

Preparation

1. If you have used a deb/ppa installation of LXD on your host machine, please install the Snap version, migrate all your containers and remobe the deb/ppa packages manually before running this script.
2. Prepare an empty folder on your host which will be shared with the container. Let's call it Shared.
3. Download and save the NVidia OptiX 6.5 installation script to Shared/Setup. You will need a developer registration at NVidia for that. As of May 2020 Mitsuba2 does not work with Optix 7.0 or higher.
4. If you wish to compile Mitsuba with non-default variants (incl. all the interesting stuff like GPU) grab the mitsuba.conf.template file from the Mitsuba2 repository and save a customized copy to Shared/Setup/mitsuba.conf.

Installation

• Download the script or clone this repository
• Make it executable: chmod +x mitsuba2lxd.sh

Be aware that this script may lead to damaging your hardware, data loss or other issues. Please check its code before running it and watch its progress. Abort in case of any errors. The license terms attached in this repository apply.

Run the script ./mitsuba2lxd-gpu.sh and wait for the setup to finish. It can take up to an hour.

Usage

Once the container is ready, you can get in and use its shell using following shell command. Make sure to substitute <container-name> for the name of your Mitsuba2 container you selected right after starting the script.

lxc exec <container-name> -- sudo --login --user ubuntu

You can also execute mitsuba directly, e.g.

lxc exec <container-name> -- sudo --login --user ubuntu mitsuba Shared/scene.xml -o Shared/scene.exr

Troubleshooting

• Various issues can occur during the installation. For example the container will be for sure get into a bad condition if internet connection drops during the setup process.
• If you didn't notice any errors during the installation, you can still encounter minor problems. Here are a few general suggestions:

1. Maybe the LXD just didn't start the container after the host rebooted. Check with lxc list if the container is running. If not, lxc start <container-name> does the job. LXD has a great and powerful CLI. Do not be afraid to dig deeper.
2. Did you replace your GPU recently or upgraded the driver at the host? If yes, the easiest solution is to run the script again and create a new container. Make sure to move any files you want to keep to the shared folder before you choose to overwrite the old container.

Acknowledgments

Mitsuba2 was created by Wenzel Jakob. Significant features and/or improvements to the code were contributed by Merlin Nimier-David, Guillaume Loubet, Sébastien Speierer, Delio Vicini, and Tizian Zeltner. Great job, thank you very much for you efforts!