I know that if I increase the substeps, certain solvers inside the pyro solver calculate extra times for each substep, changing the look of my sim. Anyone know a work around, or which attributes are affected by the change? I have a sim that I need to resolve artifacts with by using substeps, but increase the substeps changes the look! Any insight would be much appreciated!

It's kind of like painting yourself into a corner if changing the look is a show stopper, but I realize such circumstances do exist. Ask for some leeway from your director or client.

If the substeps change the flow or direction, you could conduct two simulation. Advect particles through the "approved/unchangeable" simulation, and generate a path. You could use that path to deform the substeped version and maintain the general flow/boundary of the original.

Thanks for the response! While the shape changes a bit, the biggest change I see is in the temperature and density that is output. I can probably refit the temperature, but the density is a bigger issue. Good to know it isn't a simple fix that I was just missing.

The specific issue im having is that im getting horizontal lines in my pyro, which I believe are a result of the collision object. I wish there was something like collision iterations for Pyro, because substeps appear to be the only thing that improves it.

If you're using the StaticObject for your collision object, there is another option. Try supplying a collision volume instead. Perhaps you could break up the surface of your collision object using noise? That might verify if the collision object is truly causing the artifacts in your simulation.

Thanks!