The boundaries of a fluid container not only define where the fluid can exist, but for dynamic fluids, they affect the behavior of the fluid.

By default, all the boundaries of a fluid container affect dynamic behavior in the same way a container would in the physical world. For example, Density emitting towards a boundary collides with the boundary just as smoke rising to a ceiling collides with the ceiling.

You can define the boundaries so they have no effect on fluid behavior by selecting None for the Boundary X, Boundary Y, and Boundary Z attributes. For example, when a boundary is set to None, Density emitting towards it does not collide with the boundary and continues as though the boundary were not there. Even though the fluid appears to leave the container, it doesn’t. Fluid can only exist inside a container.

You can also define the boundaries so that the fluid wraps for continuous behavior along the boundary.

To define fluid behavior at the container boundaries

1. Select the fluid container.
2. In the fluidShape Attribute Editor, modify the Boundary X, Y, Z settings in the Container Properties section.