Nodes - Meshes

Owned by thomas (Unlicensed)
Last updated: 05 Jun, 2014
3 min read

Meshes are one of the core concepts of RealFlow – regardless of whether you are dealing with grid fluids, particle fluids or RealWave particle layers. The first question certainly is: “What is a mesh?”. In RealFlow, a mesh is a three dimensional representation of the outmost particles of one or more emitters. The mesh engine puts a sort of skin over these particles to visualize the fluid’s volume. This polygon mesh can then be treated like any other object inside your 3D application. You can apply shaders and textures, even with UV coordinates, combine it with motion blurred particles, and render everything to create a convincing fluid.

 

Close view of a RealFlow mesh with visible polygons.

 

One of the most important criteria for a good mesh is the number of particles. This parameter is responsible for the quality of a fluid and also for the final mesh. The better the particle simulation, the better the final mesh. But even with smaller particle amounts it is possible to create a convincing mesh. The secret is to find the correct settings and that is, of course, not always easy. Meshing always needs a certain amount of testing to find out the working parameters and to avoid an unwanted “blobby” look with thick and round edges. Another common misunderstanding is the belief that the number of polygons (“Polygon size”) automatically improves the quality of a mesh.

Mesh creation, respectively mesh adjustment, is subdivided into a few steps:

  • Mesh settings. These are the parameters for the polygon hull, e.g. “Polygon size”, filtering and so on. All these settings directly affect the mesh’s polygons.
  • Field settings. With these parameters it is possible to control the influence between the particles and they are directly related to the used emitters, not to the mesh container. These settings are not available for Hybrido meshes. 
  • Testing and meshing. Testing is, as already mentioned, an essential part of the process. You normally have to create sample meshes for more than one frame to guarantee a consistent look of the mesh over the entire simulation range. The final mesh process should always be performed as a separate task and never during the particle simulation.

All mesh settings depend on each other in some way and this makes it more difficult for beginners to find appropriate settings. The best way is to test out the individual parameters step by step and have a close look at the results. This helps you to get a better understanding of how the parameters influence the final mesh.

Build Mesh and Build Mesh Sequence

In RealFlow there are two methods to create a mesh:

The first method is to build a single mesh. In most cases, this feature is used to create a test mesh from a single frame. It is your starting point for adjusting the mesh's individual parameters. In many cases you will do this for several frames until you have found working settings. A single mesh can be created with the “Build Mesh” button from the “Mesh” shelf:

 

 

Then, the entire simulation range is meshed. To do this, please do not reset the timeline, but rewind to frame 0, and press the “Build Mesh Sequence” button from the “Mesh” shelf. RealFlow will now go through the frames and create the meshes one by one. This, by the way, is also something that can be done with RealFlow's Command Line version:

  • Click on the small triangle next to the “Simulate” button.

  • Enable “Command line”.

  • Click again on the button's context menu.

  • Open the “Command line options...” panel.

  • Define a frame range and check the “Mesh” option.

  • Hit “Simulate”.