Core and Splash Filters

"Core" and "Splash" filters can only be used in conjunction with standard particle fluids.

The particle filters are available for all particle mesh types. Click on the mesh node's attached emitter alias and take a look at the "Node Params" panel:


Core” describes the main body of water. In real life this could be the water in a bathtub, for example. Now you throw something into the water: the object disturbs the core fluid and creates splashes.

“Core” and “Splash” are normalized – their values range between 0 and 1:

  • RealFlow reads a particle's number of neighbour particles.
  • Core fluid particles normally have a large number of neighbours, because there the particles are packed densely.
  • Splashes become thinner with increasing distance from the core fluid, and the particles have less neighbours.


What you need to separate the splashes from the core fluid are two mesh nodes. The first mesh represents the core fluid:

  • Add a particle mesh node (all types are supported) and attach an emitter.
  • Go to Node Params > Particle filter > Core and enter a value close to 0, e.g. 0.05.
  • Mesh node 01 > right-click > Build
  • It may require a few test meshes to find the final “Core” value, because it is a sensitive value.



With higher values, more and more particles will be removed from the emitter, and gaps will occur. These gaps have to be filled in again, and this is why a second mesh node is required. The splashes are used to substitute the particles you have removed from the core fluid.


For the splash part another particle mesh node is required:

  • Add a second particle mesh node (all types are supported) and attach the emitter.
  • Go to “Splash” and enter a value close to 1.
  • A good starting point is the following formula: Splash = 1 - Core
  • If “Core” is 0.05, for example, then the “Splash” value can be 0.95. Maybe you have to perform a few tests until you have found the working settings.
  • Mesh node 02 > right-click > Build



When you define different colours you will see a clear separation between the core fluid and the splashes:


Core mesh = 0.05 | Splash mesh = 0.95 | Combined meshes