The Vellum Configure Grain SOP configures the incoming geometry to be solved as grains in the Vellum Solver system. The two main options are either to convert the incoming geometry into points by treating it as a volume and filling it with grains; or tag existing points on the input to have grain-like behavior.
Grains often require more substeps than other Vellum constraint types. It is recommended any attached Vellum solver be raised to at least 5 substeps for stability.
For more control over filling a volume with grains, look at the Grain Source node.
Create Points from Volume
Treat the incoming geometry as a closed volume and fill it with points. These points are then configured as grains.
The subset of incoming points to configure for grain-like interaction.
In case the group is named or numeric, this can disambiguate what type of group it is.
Diameter of the grains. The
pscale attribute will be set to
one half this.
The mass of each individual grain.
Controls jittering of point positions.
Because relaxation can never accurately separate all particles, note
that the final
pscale will be reduced to minimize overlap.
Add Sprite Material
Adds a sprite material so the grains will display as spheres in the viewport.
Show All Points
Points that are attached to primitives do not draw their sprites by default. This will cause them to still draw the sprite, useful if combining two constraint types within the same point.