Mikrofacetmalli

Mikrofacetmalli refers to a computational method used in computer graphics and computer vision to simulate the appearance of surfaces. It is an extension of the more general facet model, which describes a surface as being composed of many small, flat surfaces called facets. The "mikro" prefix indicates that these facets are of a very small scale, often smaller than the resolution of the sensor or display being used.

The core idea behind mikrofacetmalli is to approximate the complex micro-geometry of a real-world surface at a level that is computationally manageable. Instead of modeling every single microscopic bump and irregularity, the mikrofacet model assumes that the surface is composed of an infinite number of randomly oriented microfacets. These microfacets reflect light according to the laws of reflection, and their collective behavior determines the overall appearance of the surface, including its shininess, roughness, and color.

When light strikes a surface modeled using mikrofacetmalli, it is assumed to interact with these microfacets. The direction and intensity of the reflected light are calculated based on the orientation of the microfacets and the incoming light direction. By statistically averaging the reflections from a large number of these hypothetical microfacets, the model can predict how light will scatter off the surface. This allows for the realistic rendering of materials with varying surface properties, such as polished metals, matte plastics, and rough fabrics. The distribution of the microfacet orientations is often described by a normal distribution function, which captures the statistical nature of surface roughness.