Based on original repository by NicNel.

This in turn was based on mesh_ply.py from Blender Mitsuba Add-On.

This version is updated for current master branch of pbrt-v4, tested using blender 3.6.

Blender add-ons are installed as zip archives. I would recommend either using the "Download as ZIP" option on Github, or cloning the repository and then compressing the result to a zip archive.

From Blender, navigate to "Edit" -> "Preferences" -> "Add-ons" tab, "Install..." button. Select the zip archive.

The add-on should appear as "Render: PBRTV4_Exporter" below. Make sure to tick the box to enable the add-on.

• Set your Render Engine to PBRTV4 Renderer
• Set the path to the folder containing your PBRT V4 binary (i.e. pbrt.exe) under PBRTV4 Bin.
• Set the "Project Folder" property to the directory you'd like to contain your generated .pbrt files and rendered .exr images.
• Render as usual, using e.g. F12, or by clicking the "Start Render" button.
• Optionally, if you want to just generate the .pbrt outputs and not render, select "Export scene only". You can then render at your leisure using pbrt.exe.

Render progress and info messages are printed the console (enable the console under Window -> Toggle System Console).

All materials should use PBRTV4 nodes to work correctly in the PBRTV4 renderer.

Ensure you use the PBRTV4 Output node, and not a standard Blender shader (like "Principled BSDF" for example).

Inputs such as images should also make use of the PBRT image texture node PBRTV4 Textures->Image.

For Image textures, set the mode to either spectrum (represents a colour value) or float (e.g. a displacement map) as appropriate.

Textures used as normal maps must have the is Normal property set.

Example minimal setup using the diffuse shader:

If you want to set up a participating medium inside a mesh without adding a BSDF to its surface, simply bind to only the Inside Medium (and possibly Outside Medium) node(s).

This is equivalent to setting Material "interface" in PBRT.

Currently materials do not appear correctly in the Rendered and Material Preview view modes. As a result I recommend the use of Solid or Wireframe when composing scenes.

Currently only the point, distant and spotlight light types are supported in Blender. These correspond to the blender light types Point, Sun and Spot respectively.