Hi All,

I recently made an interactive raytracer and photon mapper with Processing:

http://www.cc.gatech.edu/~phlosoft/photon/

The goal was to give intuition for how photon mapping augments a basic raytracer by letting you play around with the lighting and some spheres in realtime. Any feedback is appreciated. Thanks!

-Grant

Thanks, kof.  Bear in mind that both the speed and shortness of the code are due to the fact that this is the barest-bones implementation that can be called "photon mapping" -- you're right that there are no caustics, no sub-surface scattering -- and it is a very simple scene.

I too was surprised at the interactive speeds -- chalk it up to a victory for processing.  I honestly used to do these kinds of experiments in CodeWarrior or XCode, but it was always kind of a chore just to get up a window and start drawing pixels, so I never even tried to make anything interactive.  Processing somehow "gave me permission" to do it -- made it seem possible. </satisfied customer>

Totally agree.
grant, this is mindboggling!
Thanks for showing it.

I have to chime in with more praise.  This thing is so awesome!  Mad respect for your work Grant!  I've been playing with your code (hope you don't mind!)- I'd love to throw out a few thoughts.

First, I'm wondering about the difficulty of adding the ability to render arbitrary polys in the engine.  It appears that the code is currently wired to use preregistered mathematically defined shapes.  Maybe a method similar to beginShape() that would dynamically add the triangles to your object list.   You should be able to do that in about 10 lines of code, right?

It seems to me that if you were going to add one major update, that would be the one  It would be so cool to have a renderer like this, that was 'homegrown' from the Processing community.

Keep up the amazing work man!

Hey Grant - thanks for the response.  Yeah I've been using p5sunflow, and the results are completely amazing.  As of right now, p5sunflow doesn't do any reflective properties, and its soo slowwwww.  And Mark, the developer has too many cool projects to go full-on with it.

I don't know if yours would be any faster, but I would love to be able to have shiny reflective/refractive(?) objects.  Also, just having a raytracer that came from, and was made specifically for Processing would be great!  

I actually went as far as to look up the math for adding polygon tracing- you are right that it wouldn't be too bad.  In fact, its a matter of extending the plane-intersection part of the code.  First, check the plane which the poly lies on.  If hit, then bounding box check, if hit, then do a polygon ray test.  A very simple one is here :
http://www.siggraph.org/education/materials/HyperGraph/raytrace/raypolygon_intersection.htm  Of course, the part where you draw (register) all your polys would have to be made as well.

So the theory isn't too bad.  The hard part really is building it in a way to be useful in the Processing context, as a plugin renderer for the size() command.  *That* I know nothing about.

Whatever the case, your codez rock!