Limit the volume of a mesh's effect using boundary controls

Boundary controls are available for the various meshes involved in a Bifröst simulation, including emitters, colliders, and others. These let you limit the effect of the mesh to the intersection of the mesh and an implicit volume. For example, you can make a mesh emit only when it is inside the volume of a box or sphere.

The Boundary Controls attributes are available on the corresponding mesh properties node, and affect all meshes that share the properties node.

1. In the mesh properties' Boundary Controls, turn on Enable Boundary.

2. Select a Boundary Shape.

   The boundary's shape is represented as a unit-sized wireframe icon at the location of the properties node (by default, at the world origin).

3. Scale, rotate, and translate the properties node to define the desired volume of effect.
4. If desired, activate Invert to make the mesh's effect occur outside instead of inside the volume.