A big question when we are simulating a GridFluidDomain in RealFlow, is how to know when we can use “From Field” or “From particles” from the Surface tab “Source to” parameter. Actually you can use “from field” or “from particles” when you want, but there is a difference between them and the simulation might be affected depending what you choose. I’m going to put 3 images to explain it.
1- When you are simulating a GridFluidDomain, you should put the “Source to” parameter to “From Field”, make sure you have the checkbox checked in the Export Central to export these files, and the “Calculate surface” parameter to Always to calculate it.
2- Why do I need to use “From field” instead of “From particles”? Because when simulating splashes and foam particles, the splash won’t need to calculate it again and the field files will be read from the cache, and the simulation will be faster than using “from particles”. So we need to put the “Calculate surface” parameter in the GridFluidDomain to cache when simulating splashes or foam. The GridFluidDomain must be in cache mode too.
3- Once the splashes and foam have been calculated, we want to calculate the GridMesh for the GridFluidDomain. In this case, we’ll use “From particles”. Why? Because “From particles” adjust better the mesh to the particles than using “From particles”. Before calculating the mesh we need to put the “Calculate surface” parameter to Always to calculate the new field file for the “From particles” and change the Source to “From particles”. If you don’t change the “Calculate surface” parameter from cache to Always, the mesh will be generated with the old files which have the “From field” information.