Transient light transport in the Cornell Box using transient photon map in RADIANCE. The existing kd-tree data structure to store the photons was extended to 4D, with the photons' time-of-flight as fourth dimension. This simple example demonstrates one aspect of transient rendering that is lost in steady state lighting: it reveals fleeting phenomena that (mostly) disappear when lighting reaches equilibrium. Note the strong colour bleeding on the central white wall from the 1st bounce off the flanking red and blue walls (see t=3.0 nsec). This effect is neutralised by secondary interreflections, and barely noticeable in steady state. This example also demonstrates the current prototype's limitations; transient rendering is limited to diffuse surfaces (note the steady-state specular reflections on the dielectric sphere), and the speed of light is assumed to be constant, i.e. independent of the index of refraction.