While sipping from an excellent cup of coffee I’ve worked on the area lamp render fix, as promised to work on in exchange for the incredible espresso engine!
The above images show the old situation, with and without shadow. Note that the light doesn’t really make the sides of the sphere become lit, and for shadow this even becomes totally terminated.
This is the situation as now in svn. Now, for every possible shadow sample, an area light calculation is done from that position. This clearly gives much nicer light on the sphere (but note that the floor is identical). With a shadow render, the self-shadowing effect of faces are visible. I’ve not included terminator code for resolving phong imperfections… that fights with the whole idea of soft shadow. Better to use as small faces as possible now.
(More work on this will be done of course, this is the first commit, need to do more tests for quality)