I am simulating smoke around building rubble. I have the buildings set as smoke collision objects. However, the smoke seems to leave a huge collision padding around my objects. The buildings are to scale (1 unit = 1meter), and my smoke seems to be leaving padding of several units. It will also not flow between gaps smaller than this.
Others physics sims have options to adjust collision padding distance, but smoke does not. How do I deal with this? I see people's test videos and the like where their smoke is colliding with surfaces without any visible padding, and certainly not several units worth.