Create a Bifröst simulation

Creating a simulation adds the required Bifröst objects to a scene, and in addition connects any selected meshes as fluid emitters.

You can create more than one simulations in the same scene, but they do not interact with each other.

Note: The Bifröst plug-ins are loaded by default. If they have been unloaded and the Bifrost Fluids menu does not appear in the FX menu set, you can load them using the Plug-in Manager. See Load or unload Maya plug-ins.

Create a simulation

1. If desired, select one or more polygon mesh objects to act as emitters controlled by a single shared property. Instances are not supported.

   If you want certain emitters to use different properties, for example, to have some emit continuously and some not, you can add more groups of emitters later (see Work with Bifröst emitters).

   If you select nothing, an empty simulation will be created. You can either add emitters later or load a previously saved cache (see Work with Bifröst user caches).

2. Select Bifrost Fluids > (Create) Liquid or Bifrost Fluids > (Create) Aero in the FX menu set.
   The following items get added to the scene:

   • The main container, called either bifrostLiquid or bifrostAero. This node controls the execution of the simulation.
   • The shape, called either liquid or aero. This node represents and displays the results of the simulation as particles and voxels in the scene. It is a child of the main container.
   • The main properties, called bifrostLiquidProperties or bifrostAeroProperties. This node contains most of the settings for controlling the overall resolution and behavior of the simulation.
   • A mesh object, called bifrostLiquidMesh or bifrostAeroMesh which can contain a polygon mesh version of the shape. By default it has no polygons, but you can activate meshing in the shape's attributes.
   • A mesh property called bifrostEmitterProps. This node controls the emission from the selected emitters.
   • For liquid simulations only, the global guide properties, called bifrostGuideProperties. You can ignore this unless you want to create a guided simulation as described in Guide a Bifröst simulation of a liquid surface.

You can see and select these nodes in the Outliner. In addition, you can select the shape in a viewport by dragging across an edge of its bounding box with the Select tool.

The main container, shape, and mesh object are created at the world origin. They should be left untransformed to ensure that the results of the simulation line up with the emitters, as well as with any other objects that you add, such as colliders and other influences. Moving, rotating, and scaling the container, shape, or mesh object is useful only in specific situations, such as when loading a cached simulation into another scene.

If no particles appear in the viewport, there are a few things to check:

• Make sure that the shape is not hidden by the emitters. For example, you can switch to Wireframe display, or make the emitter into a template (unselectable), or simply hide the emitter.
• Make sure that Renderer is set to Viewport 2.0 in the viewport's menu bar.
• Make sure that the current frame is the start of the simulation that is set on the main container (by default, frame 1).
• Reduce Master Voxel Size on the main properties, in the case that the emitter objects are too small to contain any voxels.