SPH - Initial State

Owned by
thomas (Unlicensed)
Last updated: 29 Apr, 2014
2 min read

This is a very useful function to create a kind of preset from which the simulation can be resumed easily. In many cases it is necessary to create relaxed states for a fluid. Relaxed means that most of the fluid’s energy has been withdrawn and the particles are more or less still. To achieve this state it is important to perform a simulation allowing the particles to settle. When the fluid’s surface is calm, you can create an initial state, resume from this condition and execute a new interaction, for example the impact of a body. An initial state can be saved at any time and the resulting file will be stored under the “initialState” folder of your project’s directory.

 


Use Initial State

There are two options available with this setting: “No” and “Yes”. “Yes” allows you to use an initial state with the currently selected emitter, while “No” disables this possibility. Please note that initial states can be created individually for each emitter in your scene.

Make Initial State

This is the button to create and save the initial state file which will be used to resume the simulation exactly from this moment. To use an initial state with a simulation it is not enough to activate “Use InitialState” – you also have to reset to this specific point. This can be done by tagging the “Reset To InitialState” option next to the "Reset" button. With the next reset, RealFlow will load the initial state file and the simulation starts from 0 again. Existing BIN files will be overwritten with a new simulation, but normally it is not necessary to backup previously generated files. If you need them, do not forget to apply a new name for the emitter, for example.

Here is the workflow:

  • Make an initial state with the “Make Initial State” button.
  • Set “Use Initial State” to “Yes”.
  • Activate the “Reset To InitialState” option next to the “Reset” button.
  • Optional: backup your previous data or apply a new export name for the emitter.
  • Reset the scene to load the initial state at frame 0 (or any other specified frame).
  • Simulate, using the initial state.