Some comments from the designers: ____ From Greg Ward (the main author of Radiance): As for the shadow under a refracting sphere or such, I just follow the rays through the object to the light source following a refracted path, and if I hit it, I get it, if I don't, I don't.
(I; do n't; ) (I; just follow; the rays; to the light source) Context(I just follow,List([138, 151))):(I; just follow the rays following; a refracted path) (I; hit; it) (I; get; it) Context(I get,List([245, 250))):(I; don't; )
I just follow,List([138, 151)) I get,List([245, 250))
I I I I I I
do n't just follow just follow the rays following hit get don't
the rays to the light source
a refracted path
it
it