My configuration : CPU 2 cores, SH3D 0.6 GB max.

For samplerAlgorithm=fast, do you have the same type of rendering?

The multipass parameter is not yet integrated into the plug-in because it is not indicated in the PhotoRenderer.properties file.
As the MultipassRenderer.java file is present in the source code, you can test it with a SweetHome3D.l4j.ini file by adding -Dcom.eteks.sweethome3d.j3d.PhotoRenderer.highQuality.samplerAlgorithm=multipass .