GROUND STRANDS

[ 'Floating' strands are re-projected onto the surface and assigned new surface info ]

Grounding in Ornatrix is the process of attaching surface dependance information to a strand (hair or guides) object. To do this strands are 'projected' onto base mesh. Once every strand root's position relative to the mesh is determined it is cached and attached to the strands as surface info that flows up in the pipeline. Surface info is often required to compute UV coordinates, to deform guides with mesh, and to inherit other surface-related properties for modifiers such as surface comb.

To make the best use of strand ground plugin you need to understand a couple of things that it does:

1. Ornatrix always assumes that its hair are located in the same object space as the distribution mesh (ie. all operations with mesh vertices and hair strands are done in same space). Therefore, ground strand modifier will align the hair node you chose to ground with the selected distribution node. You can see this if you disable ground modifier and your previous guides aren't aligned as they're used to. This step is very necessary for further operations on guides.

2. Ground strands will use closest triangles for each guide to find a suitable place to put it. If a guide's tip is closer to a triangle than its root, it will be flipped (ie. its root considered its tip). This ensures that guides retain their relative shape, however, in some rare cases it can cause some guides to stick to undesired surface points.

Parameters:

Re-orient node - If this option is on, the hair node will be aligned with the distribution surface node before reprojecting. Sometimes this is required to get correct results.