Editing Gouraud shading (section)

== Description ==
Gouraud shading works as follows: An estimate to the [[Normal (geometry)|surface normal]] of each [[Vertex (geometry)|vertex]] in a polygonal 3D model is either specified for each vertex or found by averaging the surface normals of the polygons that meet at each vertex. Using these estimates, lighting computations based on a reflection model, e.g. the [[Phong reflection model]], are then performed to produce colour intensities at the vertices. For each [[Pixel|screen pixel]] that is covered by the polygonal mesh, colour intensities can then be [[interpolation|interpolated]] from the colour values calculated at the vertices.