We have seen the Conference Room scene before (in other posts). It was originally created for Radiance. The room does (or at least did) exist in reality and was painstakingly measured and re-created in a text editor (vi). See README file and credits in the repository, where I keep my test scenes in various formats.
One last thing to mention is that right now the C++ version and the Rust version differ a bit in rendering the plastic chairs. Here the C++ version of the first image:
And the resulting difference image (create via imf_diff):
The difference is most likely caused by the roughness value (being different from zero) in the plastic material of some parts being used for the chairs.
# black_mat MakeNamedMaterial "black_mat" "string type" [ "plastic" ] "color Kd" [ 0.05 0.05 0.05 ] "color Ks" [ 0.01 0.01 0.01 ] "float roughness" [ 0.1 ]
This will be fixed in the next release.
The PBRT file (including all cameras) for this scene can be found in the download section.