The bifrostGuideProperties attributes control the global guide settings. For more information about guided liquids in general, see
Guide a Bifrost simulation of a liquid surface.
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, 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.
Guided Simulation Parameters
Guided Simulation
-
Enable
- Enables a liquid simulation to be guided.
Guide Cache
-
Enable
- Allows Bifröst to use the user cache files. These files are needed if you add frames to a guided simulation. Normally, this option gets set automatically when you generate a user cache, but you can activate it manually if you want to load a cache into an empty simulation. See
Bifrost Caching attributes and
Work with Bifröst user caches.
Input
-
Mode
-
- Simulation
- Enables a liquid simulation to be guided by a cached, low-resolution simulation. Use
Sim Cache Directory and
Sim Cache Name to specify the cache files.
-
Mesh
- Enables a liquid simulation to be guided by animated and deformed polygon meshes in the scene.
-
Sim Cache Directory
- The directory containing the cached simulation to use as a guide.
-
Sim Cache Name
- The base file name of the liquid voxel cache files.
-
Compute Guide from High Res Liquid
- Computes a final guiding shape that takes the high-resolution liquid into account. This allows colliders to fall into the liquid and penetrate quite deeply without the need to increase
Min Simulation Depth (which would affect the number of particles and voxels required across the whole simulation).
- You can try turning this off if you experience problems, for example, if the simulation does not hold its shape in certain situations. You can also turn this off to speed up computations, but this can result in holes at the main liquid surface if the simulation is very splashy.
-
Guide Voxel Scale
- A scaling factor for the
Master Voxel Size that is used to voxelize the guide shapes. It also affects the size used to voxelize colliders — use
Collision Scale for additional control over the voxel resolution of colliders.
-
Min Simulation Depth
- The depth to simulate, below the top liquid surface in scene units. You may need to change this depending on the scale to which the scene was modeled.
- Surface Layer
- The height of the simulated layer on top of the guide surface, in scene units. This can be useful for surface splashes. There is a falloff from the full height at the center of the emission region to 0 at its boundary.
Particle Reseed
Adds particles to prevent air pockets developing between the guided liquid and the guiding shapes.
-
Particle Density
- Controls the number of particles to add per voxel in air pockets. The particle count per voxel is the cube of this value. For example, specifying 2 results in 8 particles per voxel (23 = 8). Do not use a value less than 1.0.
-
Guide Overlap,
Liquid Overlap
- Multiples of the
Master Voxel Size that determine how deeply into the guiding shape and liquid shape to reseed. You can try increasing this value if you experience volume loss, or explosive bursts (which can be caused by liquid rushing in to fill air pockets). However, values that are too high can also cause artifacts in the motion, because the reseeded particles inherit velocity from the guiding shape.
-
Interface Distance
- A minimum distance in scene units from the air-liquid boundary, below which particles are not reseeded. This prevents noise at the surface.