
Robert VISUAL2 LAB1 Nonphotorealistic rendering
Uses volumeshop application with GLSL fragment shader program
TOON1
Three colors hardcoded. User defined interval and light direction.
Shading based on dotproduct of light vector and normal vector.
TOON2
Coloring calculated based on dotproduct of light vector and normal vector.
User can select number of colors and add specular highlight.
CONTOUR1
The areas where dotproduct of view vector and normal vector are above
a threshold, are colored. Coloration based on cosine term. User can
change contour color by changing transform function.
CONTOUR2
The areas where dotproduct of view vector and normal vector are above
a threshold, are "blanked out". Below the threshold, the user can
adjust contour thickness.
COOL TO WARM
Cool to warm shading described by Gooch et.al.
RIDGE & VALLEY ENHANCEMENT
Principal curvature calculated using method described by Kindlmann.
Contours (colored black) useradjusted using curvature in view
direction. Mean curvature threshold used for emphasizing ridges
(colored white) and valleys (colored browngrey).
SIMPLE STIPPLING
Here the dot product of the view vector and normal vector is
used again. The higher the cosine term, the lower the probability
for drawing a stipple.

