Screen space silhouette and volume trails

I would like to experiment with "multiple spaces" effects.
This is the first attempt ... screen space silhouette and volume trails. It evaluates ~realtime.


It uses prim neighbours array search made by Wooshum,, from odforce.
It also uses geo cull made by F1, Links are included in the file.

The silhouette trick:

  • create array of primitive neighbours, preferably on the static geo
  • transform the geo into the camera space (toNDC)
  • almost flatten the geo in the camera space (@P.z). This exaggerates any normal angle "gradient" and flattens any peaks pointing to/from the camera.
  • angle of neighbouring primitive normals to get the silhouette

Here is the .hip file.