Square pattern and stair-steping issue in Simulation

[rconover]

I have checked the scene and this stepping is normal and unavoidable because FumeFX uses voxels for simulation and your mesh source is slightly sloped.
You could maybe smooth it out a bit if you set the object source type from solid to volume.

Regards,
Kresimir Tkalcec

Another trick that sometimes helps is to have Fume calculate 5-10 or so fames early and key the emitter's rate for the timing that you want. Maybe I'm deceiving myself - but i feel it lets Fume pre-stir the voxels a bit so they birth more oganically. Otherwise you might need to hide the source and have the effect emit through the floor or something. Also for tiney detailed fire I find emitting from a tiney detailed geometry (a geometry with most of the poloygons deleted in a random fashion-leaving only a few scattered polygons) and a tiney detailed noise map (or both) help a lot to scatter flame accross a surface more realistically.