Gouraud shading
More info
- Creator
- Henri Gouraud
- Released
- 1971
- Type
- Shading technique
A way to smooth out faceted 3D surfaces by interpolating light values across the vertices instead of shading each polygon flat.
Henri Gouraud described the technique in 1971 at the University of Utah. Rather than give each polygon a single brightness, the lighting is computed at the corners and ramped linearly across the face, so a coarsely tessellated sphere reads as round rather than blocky.
It is cheap enough to run in real time, which made it the default for early 3D — from arcade cabinets and the PlayStation to the shaded vector objects of the demoscene. The cost is that specular highlights smear out or vanish entirely between vertices; Phong shading works per pixel and catches them, but costs far more.