Shadow map sizing

Hello guys,

While playing with shadows in Play Canvas I ran into quite an unpleasant issue with my scene: basically, the scene is quite big (in terms how much world units the camera sees), but the bounding box of all shadow casters is quite small – imagine an exhibition hall with an item in the center of it – all the surroundings are basically empty / not affected by shadows. However, the shadow map always gets rendered so that the whole visible area (limited by shadow distance) gets into shadow camera's view.

Just a random thought: would it make sense to try adjusting shadow camera frustrum so that it captures the volume = MIN(visible scene BB, shadow casters BB)? I am looking into trying to play with it but a bit afraid that I am missing something crucial and will just waste the time before running into a stone wall – or it's actually worth trying?