Minor fix
Minor chqnge
solid angle now taken into account when indexing in the envmap
piecewise-constant distribution built from envmap -- Importamce Sampling to be done
Missing files
Segfault in importance sampling
segfaults due to NaN values to fix ... :/
Importance sampling OK
c
nothing much
Importance Sampling is coherent (see pics/IS-env-4096.png)