Reply To: The collision physics are not rendering. The smoke is just going through the floor but when I play it back in the viewport render it looks correct. What am I doing wrong?

Did you maybe check “High Resolution” in the  “Smoke” panel of the “Physics” tab of your smoke domain (see bottom right corner in the image below)?

This “High Resolution” effect is a kind of displacement done after the physics calculations have been finished and therefore doesn’t respect any collision objects