An interactive ray-tracing tutorial system

Depends what you mean by ray-tracing.

You can recursively trace shadowed spheres in ~10 lines, but that's not really interesting.

To handle non-trivial scenes, you'll need an acceleration structure of some sort (grid, BVH, BIH, SKD, kd-tree etc...) to alleviate quadratic intersection cost.

Then you can make the "shading" part as arbitraly complex/expensive as you want.

Note that on modern cpu, ray/s are measured in million.

If you really want to get into ray-tracing I recommend reading this. It might be a little advanced to begin with but he covers almost everything you could want to know about the subject and the results of his work are truely jaw dropping.

rate++ for the PBRT book linked by motorherp.

Ray tracing's really very, very easy. One of the easiest things in computer graphics. It's much easier than writing a scanline or reyes renderer, for example.

Doing it well, and doing it fast is very difficult.

What exactly do you mean by an "interactive raytracing system"? Do you mean that you want to write something like on the page you linked to, which is an interactive lesson on what raytracing is? Or do you want to write an interactive raytracer, that will let you render scenes in realtime so you can interact with them?

Quote:

Original post by Motorherp If you really want to get into ray-tracing I recommend reading this. It might be a little advanced to begin with but he covers almost everything you could want to know about the subject and the results of his work are truely jaw dropping.

This is really one of the best books in CS I own and most probably one of the best in CG programming currently available. But it is not easy and I don't suggest it to you for the following reasons:
-Half of the book covers topics you wont need unless you go a bit further into RT (GI, Caustics, Volumetrics, SSS and advanced BRDF's).
-Some really basic infos are not given: IIRC Phong shading is not described (because not physically correct) and there is no introduction to the ray-tracing.

Definitely a book to have if you are more than serious, though.

A good introduction to RT can be found here:
a 7 chapters tutorial that introduces you to raytracing with topics as ray-geometry intersection, lighting and kd-trees for intersections acceleration.

That book really seems very good...

They have a free chapter at their book page. And quoting Motorherp, some of the images on their gallery are really "truely jaw dropping".

Quote:

Original post by playmesumch00ns rate++ for the PBRT book linked by motorherp. Ray tracing's really very, very easy. One of the easiest things in computer graphics. It's much easier than writing a scanline or reyes renderer, for example. Doing it well, and doing it fast is very difficult. What exactly do you mean by an "interactive raytracing system"? Do you mean that you want to write something like on the page you linked to, which is an interactive lesson on what raytracing is? Or do you want to write an interactive raytracer, that will let you render scenes in realtime so you can interact with them?

Yes, fast ist difficult. Check this : www.realstorm.de (its in english)
I know one of them. Completly crazy germans...