Triangles are good, but don't support for instance, boolean operations, as other raytraced primitives would allow.
A raytraced box would need a transformation matrix and 2 corners. An axis aligned box isn't hard to render, so, if you transformed all the rays to the local transformation of the box, the rays would be axis aligned with regard the box, and the effect would be the same, but the box could perform any kind of rotations, scalings and translations, and would still have shadows, reflections, refractions and any other type of raytraced effects without missing parts.
This same approach can be used to render other primitives, like cylinders, or capsules, And stretching the rays along the local transformation of an object would allow to render moving ellipsoids, cones and more complex figures, only using mathematical approaches, and totally perfect. The real drawback is that this would require an horde of matrix transformations IN THE PIXEL SHADER that could be very expensive for a real time application. Though i still remember an old raytrace demo and it performed all of this, and more... (volumetric fog, boolean operations, texture mapping, reflections, refractions....) And all in a PII @ 350 mhz So who knows?...
I found it! XD
http://www.youtube.com/watch?v=tCMo-bJQC8A"There is nothing truly useless, it always serves as a bad example". Arthur A. Schmitt
