SELF-SHADOWING

Ornatrix implements a unique internal algorithm for its fast raytracer and rasterizer that allows a quick computation of true hair self-shadowing. Self shadowing adds a very key element to overall hair appearance. Besides adding cues to where all the scene lights are it adds volume to hair and enables the eye to distinguish which hair appear in front and which are in the back. Furthermore it makes effects such as backlighting possible when used with a translucent shader. Because hair transmits light throughout its volume, less denser areas when lit from the back will appear to 'glow' more than the dense ones.

Some parameters of self shadowing can be controlled. The coefficient controls how much shadow is actually applied to the hair. A value of 1 is the 'natural' value, however, sometimes it is required that shadows don't fully attenuate all the light so other values can be used. Furthermore the shadow detail can be controlled through the size of the shadow map. The bigger the map the better the detail will be causing slower render times. Softness of shadows can be controlled through a filter kernel size. This filter samples the shadow in nearby voxel volumes and averages them to produce softer and more realistic shadows.