Mitsuba 2 Blender Add-On

Author: Baptiste Nicolet.

This Add-on allows to export a Blender scene to Mitsuba 2's file format.

How to install the Add-on

⚠️ Before installing the add-on, make sure that Mitsuba 2 was compiled with the same major version of python that Blender uses (3.7x for Blender 2.82)

There are two independent ways of installing the addon, depending on your needs:

Option 1: In Blender.

• Download the latest release or clone this repository as a zip archive.
• In Blender, go to Edit -> Preferences -> Add-ons -> Install
• Select the downloaded archive
• Enable the Add-on:
  • Point Path to Mitsuba 2's build directory. If the environment variable MITSUBA_DIR was set (cf. Mitsuba 2 install instructions), this field will automatically be filled with the path it contains.
• Save the preferences. The Save Preferences button is in a menu in the bottom left corner of the preferences window.

⚠️ If you can't find the add-on in the add-ons list, make sure the Testing category is selected.

Option 2: Installing the Add-on from the repository.

There are a couple ways to keep up to date with the repository without doing the method described above every time. You can do either of the following:

• Clone the add-on wherever you want in your system, and create a symbolic link to the cloned repository location in the addons folder of Blender. This directory is stored:
  • Linux: $HOME/.config/blender/2.82/scripts/addons/
  • MacOS: /Users/$USER/Library/Application Support/Blender/2.82/scripts/addons/
  • Windows: %USERPROFILE%\AppData\Roaming\Blender Foundation\Blender\2.82\scripts\addons
• Alternatively, create a directory called addons in the location of your work and clone this repository there. Then specify the path to the parent folder of the addons directory in the preferences in Blender ( Edit -> Preferences -> File Paths -> Scripts). For more detailed information, see here.

After that, follow the same procedure as option #1

Make sure you restart Blender to update the Add-on.

How to use the Add-on

The current scene can be exported as a Mitsuba 2 scene under File -> Export -> Mitsuba 2

Some log messages are printed the console. To see them under Windows, enable the console window under Window -> Toggle System Console. Under MacOS and Linux, run blender from the command line.

What's supported ?

Currently, this add-on only allows you to save a Blender scene as a Mitsuba 2-compatible scene. Future versions may support more fancy features, such as custom nodes for materials or in-blender rendering.

Export of the following is supported:

• Objects:
  • Meshes
  • Metaballs
  • Text
  • Nurbs surfaces
• Material Nodes:
  • Diffuse BSDF ⚠️ Mitsuba 2 does not handle rough diffuse BSDFs currently
  • Glossy BSDF
  • Emission BSDF
  • Glass BSDF
  • Image Texture
  • Vertex Colors
  • Mix Shader
  • Add Shader ⚠️ Adding two BSDFs is not supported
• Light Sources:
  • Point Light
  • Spot Light
  • Sun Light
  • Area Lights ⚠️ Ellipse area lights are not supported
  • Environment Maps