The Bifröst liquid emitterProps control the emission from mesh objects that share this property. See Work with Bifröst emitters.
The emissionregionProps share the same attributes plus Death Age, but apply to meshes used as emission regions in guided liquid simulations. See Guide Bifröst liquid with a planar mesh in defined regions.
Container Attributes
- Enable
- Enables evaluation of the entire container node.
- Evaluation Type
- Controls how the node is evaluated. Normally, this should not be changed.
- Simulation
- The node gets evaluated based on the previous frame.
- Property
- The node is used only to set values used by other nodes.
- Mesh Property
- The node is used to set values on polygon mesh objects, such as emitters, colliders, accelerators, and other meshes used in a simulation.
- Per Frame
- The node is evaluated every frame, but does not depend on the previous frame. This mode can be used for animation or reading cache files.
Properties
- Enable
- Enables liquid emission from the associated emitters.
- Continuous Emission
- Refills voxels that become empty with more particles. Keep this on for liquid sources like spouts and jets, or turn it off for a pool or single drop of liquid.
Conversion
Controls how the object's volume is voxelized.
- Mode
- Controls how the object is voxelized:
- Solid creates a solid volume including the mesh interior. The mesh should be both manifold and watertight.
- Shell create a thin shell around the mesh surface. In this mode, Thickness should typically be 1.0 or more.
-
Solid (Robust) is an alternative to Solid that usually gives better results for volumes with fine detail, openings leading to cavities, or non-watertight surfaces. However, it does not handle fluids inside completely enclosed regions.
- Coarsen Interior
-
Saves memory by performing additional coarsening of the voxels inside the volume when Mode is Solid (Robust), especially with self-intersecting meshes.
- Offset Surface Distance
-
The distance in voxel widths used to close (dilate and then erode) the solid voxels when Mode is Solid (Robust). The internal minimum is 1.0 so only values greater than that have an effect. High values can create artifacts.
- Thickness
- The amount, in voxel widths, to thicken the volume. For solid volumes that are already quite thick, you can use 0.0 for the exact mesh boundary or even negative values to shrink the volume along its surface normals. For thinner volumes and shells, you should use larger values to prevent holes.
- Voxel Scale
-
Scaling factor for the Master Voxel Size used to initially voxelize meshes that share this property. See Control the voxel resolution of a Bifröst simulation.
Emission
- Death Age (emission region only)
-
Length of time in seconds that a particle can be outside its emission region before it is deleted.
Physical Attributes
- Density
- The physical density of the fluid in kg/(grid unit)3. A value of 1000 corresponds to the density of water if 1 unit = 1m.
Note: Density does not affect the rate at which particles are emitted.
- Expansion Rate
- Expands or contracts the liquid within the emitter. Positive values push particles out of the emitter in all directions, while negative values pull particles in, and a value of 0.0 neither pushes nor pulls.
For example, to fill a container from the bottom, you can use a positive Expansion Rate to push particles out of the emitter, in combination with Continuous Emission to refill the emitter as it empties.
Mathematically, this value defines the divergence that Bifröst tries to maintain in each voxel of the emitter's velocity field. A value of 0.0 corresponds to an incompressible fluid.
Stickiness
- Strength
- The amount that the fluid from this emitter adheres to nearby colliders.
- Bandwidth
- How close the fluid from this emitter needs to be to a collider for the stickiness to affect it, in world-space units.
UV Projection
Defines UV coordinates that get advected with the particles. Select a Projection, and then click Tool to activate a manipulator to adjust the projection.