I remembered that there was a "ray tracing theroy and implementationseries" by Jacco on Devmaster website.
However, there are some website redesign of Devmaster recently, and I can't find the articles.
May you tell me where I can find the articles?
From another topic:
Not all the articles have been migrated yet from the old site, but will be done soon.
The articles had recovered, however, the following code was missing