This tool can be applied, for example, to objects such as taps or candle wicks as it creates a continuous flow of fluid. This tool is similar to Source from Surface. Both create a continuous flow of fluid; however, this tool is applied to closed volume objects. It will not work with open volume objects, such as grids or curves.
Keep in mind, this tool generates volume based fluid, as opposed to the Emit Particle Fluid tool which generates particle based fluid.
If you are sourcing from an object that deforms, or collides with a deforming object, the solvers (smoke solver, fluid solver, and pyro solver) do not pay attention to the per-point deformation. You need to set the Velocity Type to Point Velocity, which is a parameter on the Fields ▸ Sources subtab of the solvers.
Using Source from Volume
Create a geometry object with a closed volume within a container.
Select the geometry object to generate the source.
Click the Source from Volume tool on the Volume Fluids tab.
Select the container to put the source into and press Enter to confirm your selection.
This tool is different than using Smoke from Object, Burn from Object, and Liquid from Object because it emits fluid continuously. It also useful as it allows you to create and simulate multiple objects in the container, whereas the other tools set the initial conditions from one object.
If the object is only partially in the container, only the portion of the object that is in the container’s boundaries will be simulated.
This tool is similar to Sink from Objects and Pump from Objects as it converts a geometry object into a dynamic object with a Merge node that has a default Relationship. Changing the Relationship field in the merge node will change the action of the tool. For example, you can change a Sink from Object to a Source from Volume by changing the Relationship from Sink Relationship to Source Relationship in the drop-down menu.