Buildings from scenes are now merged in a single mesh in Mitsuba update (from 3.5.2 to 3.6.2) HELP!

[pablosreyero]

Dear Sionna Community,

I just upgraded to Sionna 1.1.0, and the code I used to create 2D scenes out of 3D scenes is now useless due to Mitsuba's 3.6.2 update, as all buildings are now under a single mesh. My code iterated through each building inside a given scene to reconstruct the whole scene in 2D, but now I don't know how to identify which vertices belong to which building, and this is a big problem as I cannot use the new version of Sionna to conduct my research. Is there any way I can identify the vertices of each building separately?

Thanks in advance for your support,

Pablo.-

[merlinND]

Hello @pablosreyero,

In Sionna 1.1.0, shapes in the scene are automatically merged in order to improve performance. This is not related to the Mitsuba update.

You can disable this merging by passing merge_shapes=False or a regex based on the mesh IDs (merge_shapes_exclude_regex) to the load_scene() function.
Documentation: https://nvlabs.github.io/sionna/rt/api/scene.html#sionna.rt.load_scene

[pablosreyero]

Hi @merlinND,

My bad, thanks for the quick response and sorry for my misunderstanding,

Pablo.-