a given 2D polygon along the Z-axis. genrev creates a surface of revolution from a given function. genworm creates a worm given four functions - the (x, y, z) coordinates of the path, and the radius of the worm. gensurf creates a tesselated surface from a given function. gensky creates a description for a CIE standard sky distribution. Geometry converters Radiance includes a number of programs for converting scene geometry from other formats. These include: nff2rad converts NFF objects to Radiance geometry. obj2rad convert Wavefront .obj files to Radiance geometry. obj2mesh convert Wavefront .obj files to a Radiance compiled mesh. This can then be included in a scene using the recently added mesh primitive. More efficient than using obj2rad and includes texture coordinates. Rendering rpict is the renderer, producing a Radiance image on its standard output. rvu is an interactive renderer, opening an X11 window to show the render in progress, and allowing the view to be altered. rtrace is a tool for tracing specific rays into a scene. It reads the parameters for these rays on its standard input and returns the light value on standard output. rtrace is used by other tools, and can even be used to render images on its own by using the vwray program to generate view rays to be piped to it. dayfact is an interactive script to compute luminance values and daylight factors on a grid. findglare takes an image or scene and finds bright sources that would cause discomforting glare in human eyes. mkillum takes a surface (e.g. a window or lamp shade) and computes the lighting contribution going through it. This data is then used by the illum material modifier to make lighting from these secondary sources more accurate and efficient to compute. Image manipulation and analysis pfilt filters an image. The common technique to achieve anti-aliased images is to render several times larger than the desired size, and then filter the image down using pfilt. pcompos composites images, either with anchor coordinates or by adding several images on top of another. pcond conditions images. Can simulate a number of effects of the human visual response e.g. defocusing dark areas, veiling due to glare, and colour loss due to mesopic or scotopic vision in low light. pinterp interpolates between two images provided they both have z buffers. Uses rtrace to fill in gaps. Is used to speed up the rendering