  We describe several extensions to TIM, a raytracing program for ray-optics
research. These include relativistic raytracing; simulation of the external
appearance of Eaton lenses, Luneburg lenses and generalized focusing
gradient-index (GGRIN) lenses, which are types of perfect imaging devices;
raytracing through interfaces between spaces with different optical metrics;
and refraction with generalised confocal lenslet arrays, which are particularly
versatile METATOYs.
