I'm just learning about volume sims and came across these two types of pyro solver (Pyro Solve and Pyro Solve Sparse).

What is the difference between them, and what are the benefits/disadvantages of using one over the other?

Without going heavily into technical details and someone correct me if I'm wrong. A sparse solver will by default only compute voxels that has a density value, while the regular solver will compute and store every voxel inside the simulation bounding box. If you have a rocket flying in an arch, the bounding box will easily get huge and contain tons of empty voxels. A sparse solver will help eliminate all those voxels that are "empty".

I am sure there are specific cases where you'd want to use the regular solver, but for most cases you can use the spare solver which will be faster and require less memory.


PS! Before sparse solvers, a workaround was to split large simulations into multiple solvers with smaller and slightly overlapping bounding boxes. I assume something like this is what the sparse solver is doing under the hood.

Thanks for your explanation Trontrond.