Several illustrative techniques were implemented using GLSL:
- Cool-to-Warm (Gooch)
- Drawing (several contour-techniques combined to simulate a sketch)
- Gradient based contours
- Curvature-controlled contours
The techniques also has several options and variations (gooch with/without splashback, etc..)
A normal direct volume rendering using Blinn-Phong shading.
Changed Blinn-Phong shading to cartoon-shading.
Turned on curvature-controlled contours.
Also turned on gradient-based contours with low exponent for a bit more shading (depth-feeling).
Gooch cool-to-warm shading.
Gooch with curvature-controlled contours.
Gooch with curvature-controlled contours and splashback (for more depth).
A technique sometimes used in photography, by placing two strobes at opposite sides gelled with cool and warm gel, where the light meet it will be combined to white light..