Accelerators can be used to move fluid around in a Bifröst simulation, for example, to create a jet of water for a fountain or a fan blowing smoke. The particles' velocity is affected as long as they are within the influence of an accelerator object.
Add accelerators
- Select one or more polygon meshes to act as accelerators (instances are not supported), as well as either one of the following:
- The main container (e.g.
bifrostLiquid or
bifrostAero) to add all selected meshes to a new shared accelerator property. Alternatively, you can select the shape (e.g.
liquid or
aero)
- An existing accelerator property to share its attribute values with the selected meshes.
- Select
.
Remove accelerators
- Select the following:
- One or more existing accelerators
- Either the container (e.g.
bifrostLiquid or
bifrostAero) or the shape object (e.g.
liquid or
aero).
- Select
.
When you remove the last mesh that uses a particular property, the property node is removed as well.
Control acceleration
Use the attributes in the
group of an accelerator property to control how the associated meshes affect the fluid. See
Bifröst AcceleratorProps attributes.
There are several different ways that accelerators can affect the simulation:
- Inherit Velocity applies an acceleration based on the accelerator mesh's motion. The effect is cumulative, so the particles' velocity continues to increase while they are within the accelerator's influence.
- Direction and
Direction Magnitude define an acceleration vector that is independent of the accelerator's motion.
- The boundary layer settings gradually match the particles' velocity to the accelerator's velocity. This can be used to pull the particles along with the accelerator, or in the case of a static accelerator it can emulate a drag force.
- Influence is a multiplier for the overall effect of the accelerator. You can paint this attribute to modulate the effect across the accelerator's surface (see
Paint Bifröst attributes).