In fluids, foam masks restrict foam generation to the interior of the volume of the mask mesh.
All foam masks in a simulation are converted to voxels, which are then used to determine whether a region is inside the corresponding volume or not. The Conversion options control how the associated masks gets voxelized. For foam masks, the base width of each voxel is the product of the Base Voxel Size setting in the Simulation Parameters, and the Voxel Scale setting in this panel.
Foam Mask Conversion Parameters rollout
Conversion group
- Mode
- Controls how the object is voxelized, either Solid, Shell, or Solid (Robust).
- Solid creates a solid volume including the mesh interior. The mesh should be both manifold and watertight.
- Shell creates 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, this setting does not handle fluids inside completely enclosed regions.
- Coarsen Interior
- Saves memory by performing additional coarsening of the voxels inside the volume when the conversion mode is Solid (Robust), especially with self-intersecting meshes.
- Surface Offset
- Sets the distance in voxel widths used to close (dilate and then erode) the solid voxels when the conversion mode is Solid (Robust). The internal minimum is 1.0 so that only greater values have an effect.
Note: High values can create artifacts.
- Thickness units
- Sets whether thickness is in voxels or world-space units. When set to Voxels, the effective thickness depends on the simulation's Base Voxel Size.
- Thickness
- Sets the amount to thicken the mesh. For solid shapes that are already quite thick, you can use 0.0 for a precise boundary or even negative values to shrink along the surface normals. For thinner volumes and shells, you should use larger values to prevent holes.
- Voxel Scale
- Sets a scaling factor for the base voxel size used to initially voxelize meshes that share this property.
Foam Mask Boundary Controls group
- Enable Boundary
- Enables boundary control to limit the area affected by the foam mask.
- Create Helper
- Creates a Volume helper object in the scene. The valid types for boundaries are Box and Sphere.
- None
- Picks a Volume helper already added to the scene. The button will update with the name of the currently-selected helper.
- Invert
- Inverts the area of the boundary.