Foam Mask Objects

In fluids, foam masks restrict foam generation to the interior of the volume of the mask mesh.

• Create panel > Geometry > Fluids > Setup rollout > Simulation View > Solver Parameters panel > Foam Mask Objects > Foam Mask Objects

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 Master 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 Master 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 Master Voxel Size used to initially voxelize meshes that share this property.