Rendering multiple smoke/fire domains I have several smoke domains and sources that each start a fire at a different time (frame).

now it seems that I have an issue with black rectangles that appear, which is my domain.

After reading this question: Is it possible to have more than one smoke simulation in the same scene?
I've tried to put my domains and sources on different layers, but it didn't work.

Next I removed all my domains and added one huge domain.
This doesn't seem to produce the black rectangles, but now my smoke/fire all starts at the same time and the flames/fire are a bit different now.

Any suggestions on how I can render my multiple smoke/fire domains properly?
(in viewport preview everything was fine)
If you haven't already, you will want to assign a flow group for your smoke domain and place your emitter into a group.

First, select your emitter and assign a group to it (alternative way to group would be to select the emitter, go to the Object tab -> Groups, assign a group and give it a name).

For your smoke domain, under the Physics tab -> Smoke Groups, set the Flow Group to the group you just made. This will prevent mixing of other emitters with that particular domain, allowing multiple domains to be in the same area and layer.

EDIT: One last thing I forgot to mention, make sure each domain has their own material.

And be warned: This may greatly increase render times, so consider placing them on separate layers regardless.