Gouraudskuggning

Gouraudskuggning, named after its inventor Henri Gouraud, is a technique used in 3D computer graphics to approximate the shading of curved surfaces. It was developed in 1971 and is a form of interpolative shading, meaning it calculates color values at specific points and then smoothly interpolates between them.

The process begins by calculating the color at each vertex of a polygon, typically using a lighting model that considers the surface normal at that point and the light sources in the scene. These vertex colors are then interpolated across the face of the polygon. For a triangle, the color at any given point within the triangle is determined by a linear interpolation of the colors of its three vertices. This results in a smooth gradient of color across the surface, giving the illusion of a curved or smoothly lit object.

Gouraudskuggning is computationally less expensive than some other shading methods, such as Phongskuggning, making it suitable for real-time applications. However, it can produce noticeable artifacts, particularly around specular highlights, where the interpolated colors may not accurately represent the true lighting of the surface. Despite these limitations, it was a significant advancement in computer graphics and remains relevant in certain contexts.