Our temporal caching
method reuses irradiance and radiance records in multiple frames. When
computing the global illumination solution for the current frame (a),
our method estimates where the lighting changes using simple
observations. For each record generated in current frame (b), our
temporal weighting function estimates the future change of lighting and
defines the lifespan and temporal gradients of each record (c), green
and red colors respectively representing long and short lifespan. Since
a record is reused in several frames, the computation cost of the
global illumination solution for next frames is drastically reduced.