Thanks Andrew, that 'c' variable was giving me a headache ;) ! I have updated the article with your remarks.
BTW, I have listed a few good resources about raytracing at the bottom of the page: Do you know any other good books/websites ?
BTW, I have listed a few good resources about raytracing at the bottom of the page: Do you know any other good books/websites ?
Scratchapixel was new to me, so thanks for that link. PBRT (which you already have) is definitely a favorite. You also cited Graphics Gems IV but I enjoy dipping into all of them. Other suggestions:
* http://tog.acm.org/resources/RTNews/html/ (Somewhat dead, but the archives are great)
* http://ompf2.com/ (Active, lots of ray tracing specific discussion)
* http://www.realtimerendering.com/ (I'm fond of the book as well)
* http://kesen.realtimerendering.com/ (Especially the sections for "Symposium on Interactive Ray Tracing" and it's successor, "High Performance Graphics")
If I had to pick one, though, it'd be PBRT since it's a unified work that starts from the ground up.
Demo here: http://antirez.com/misc/rt.html
We did a real time raytracer with 2 spheres where you could move around one with C and a cluster of DEC Alphas 20 years ago, funny to see this on my laptop in Javascript (!) now.