# PhBRML: Glossary

## Physically Based Surface Node

Node describing light-emission and scattering at surfaces in a physically based manner. One of

- PhBHomogeneousSurface
- PhBTexturedSurface
- PhB3DTexturedSurface
- PhBLayeredSurface
- PhBInterpolatedSurface

## Physically Based Medium Node

Node describing light-emission and scattering inside volumes in a physically based manner. One of

- PhBHomogeneousMedium
- PhBTexturedMedium
- PhBInterpolatedMedium

## Texture Projection Node

Node describing a transform from 3D local object position coordinates to 2D texture coordinates. One of

PhBProceduralTextureProjection

## Geometry Distortion Node

Node describing a transformation from 2D or 3D texture coordinates to 3D geometry distortion vectors used to distort object normals or geometry (dump and displacement mapping). One of

- PhBSurfaceDistortion
- PhBVolumeDistortion

## Emitter Node

Node expressing the directional distribution of self-emitted light. One of:

- PhBDiffuseEmitter
- PhBPhongEmitter
- PhBSampledIsotropicEmitter
- PhBTextureEmitter
- PhBProceduralEmitter

## Scatterer Node

Node expressing the directional dependence of surface light scattering (reflection and transmission) properties. One of:

- PhBDiffuseReflector
- PhBPhongReflector
- PhBDiffuseRefractor
- PhBPhongRefractor
- PhBSampledScatterer
- PhBProceduralScatterer

## Spectrum Node

A node describing intensity of light as a function of wavelength. One of:

- PhBLxySpectrum
- PhBXYZSpectrum
- PhBMonochromaticSpectrum
- PhBBlackBodySpectrum
- PhBSampledSpectrum
- PhBTabulatedSpectrum
- PhBProceduralSpectrum
- PhBMixedSpectrum
- PhBInterpolatedSpectrum

## Texture node

A texture is considered a function of two coordinates (u,v), texture coordinates, that returns a array of floating point numbers in the range [0,1]. The number of channels varies according to the image. One of:

- ImageTexture
- PixelTexture
- MovieTexture
- PhBProceduralTexture

## 3D Texture node

A 3D texture is a function of 3D coordinates that returns an array of floating point values. Except taking 3D coordinates as input, its semantics are identical to that of a 2D texture node. One of:

- PhBProcedural3DTexture

## Phase function node

Describes the direction distribution of light scattering in a participating medium. One of:

- PhBIsotropicPhaseFunction
- PhBProceduralPhaseFunction

## Interpolator node

A node expressing some interpolated quantity as a function of a key value. Used for key-frame animation, similar to interpolator nodes. One of:

- PhBInterpolatedSpectrum
- PhBInterpolatedSurface
- PhBInterpolatedMedium

## PhBBackground node

A node expressing background radiance [W/m^2 sr] incident on the scene. The radiation is supposed to emanate from far away, so it is a function of incident direction only for all points in the scene.

- PhBTexturedBackground
- PhBProceduralBackground