BRDF(双向反射分布函数)BRDF- Bidirectional Reflectance Distribution FunctionDescribe how light is reflected from a surfacePreliminary forBRDFBRDF: definition andPropertiesBRDFModelsBRDF Measurement
BRDF(双向反射分布函数) • BRDF – Bidirectional Reflectance Distribution Function – Describe how light is reflected from a surface • Preliminary for BRDF • BRDF：definition and Properties • BRDF Models • BRDF Measurement
Illumination(光照、照明): Illumination can be classified as local orglobal.is concerned with howLocalilluminationobjects are directly illuminated by lightsources.- Global illumination includes how objects areilluminated by light from locations other thanlight sources, Including by reflection of otherobjects and refraction through objects
Illumination(光照、照明) • Illumination can be classified as local or global. – Local illumination is concerned with how objects are directly illuminated by light sources. – Global illumination includes how objects are illuminated by light from locations other than light sources, Including by reflection of other objects and refraction through objects. Local illumination
Illumination(光照、照明). Illumination can be classified as local orglobal.Localillumination is concerned with howobjects are directly illuminated by lightsources.Today's Topic: a physical description of howlightisreflected from a surface,whichisknownasBRDF
Illumination(光照、照明) • Illumination can be classified as local or global. – Local illumination is concerned with how objects are directly illuminated by light sources. – Global illumination includes how objects are illuminated by light from locations other than light sources, Including by reflection of other objects and refraction through objects. Today’s Topic: a physical description of how light is reflected from a surface, which is known as BRDF
Preliminary: Before introducing BRDF, we review somepreliminary concepts.-SphericalCoordinate(球面坐标)- Solid Angle(立体角)ForeshortenedArea（投影面积）Radiant Energy (光能)-RadiantFlux(光通量)Irradiance（辉度）一Intensity（发光强度）一Radiance（光亮度）
Preliminary • Before introducing BRDF, we review some preliminary concepts. – Spherical Coordinate (球面坐标) – Solid Angle (立体角) – Foreshortened Area (投影面积) – Radiant Energy (光能) – Radiant Flux (光通量) – Irradiance （辉度） – Intensity （发光强度） – Radiance （光亮度）
Spherical Coordinate(球面坐标). Since light are mostly expressed in terms ofdirections, it is generally more convenient todescribe them by spherical coordinates rather thanby cartesian coordinate vectors.Z0OX
Spherical Coordinate (球面坐标) • Since light are mostly expressed in terms of directions, it is generally more convenient to describe them by spherical coordinates rather than by cartesian coordinate vectors