force_table_of_contents #
Select a fraction of a dense groom to use as simulation or deformation guides.
Selected hairs will be roughly evenly distributed across the skin.
See also: hair_extract_clumps to identify clumps and select a single representative guide.
Forced Selection #
An optional third input may be provided to forcibly include curves near the roots of these provided curves. This can be used to add growth/clump guides along side an additional selection of dense curves to use as simulation guides.
Alternatively, a specific selection of the dense curves may be selected and set as an input to get very specific guide selection for certain areas, but then rely on the random choice of this node to provide selection for other areas.
Selection Weights #
By default, guide selection is only based on getting an even distribution of points, choosing the closest root to a selection of evenly distributed surface points.
A more advanced mode may be chosen where other criteria is considered as well, such as:
* Root Distribution: Select guides with an even distribution across the surface.
* Guide Length: The longest guide will be selected. This is important for situations where the most proximate curve is very short and we want to try to select a longer guide instead.
* Guide Straightness: Straighter guides can often provide better results than ones that have a lot of bends.
* Surface Normal Alignment: Guides that stick straight off the skin can sometimes be preferable to ones that are flat to the skin.
Density Mode #
By default, selected guides have a uniform density, but this may be overridden by a density mask point attribute on the mesh.Additionally, a mask can be calculated based on mesh curvature.
If a curvature mask is used, the specific values to get a good selection will need to be dialed in.
Curve Collision Radius #
Each guide roughly represents a clump of the dense groom and are often used in simulations. Since we are evenly distributing the selection, we can determine curve width based on the proximity to its neighbors.
Note that since the curve radius is determined by the proximity to its neighbors isolated guides may have a very large radius.
Shrink Large Outliers will force the curve radius to be the average if it is larger than the third standard deviation away from the average.