I would like to provide runnable version of the current incarnation of my raytracer.
I know it's nothing special, but maybe someone would like to run it, just for fun, I know I would.
Unpack the zip archive and there you have it - double click on reddot.jar or type:
java -jar reddot.jar -Xms1g -Xmx1g
(if you care about the performance it is acutally a lot, lot better if you specify those options from command line, because if not, jvm will get too little memory for photons, and GC will trigger like crazy)
It reads obj files (with its material representation) straight from blender exporter.
But since camera is fixed I didn't provide a gui for importing your own scenes yet.
Image is updated every each 5 seconds.
Moreover, rendering fashion depends on 3 parameters:
- initial radius = (world_max - world_min).length / 50
- photons_per_pass = 100000
- alpha = 0.5
Initial radius just like in regular photon mapping is a tradeoff between smoothness and details. If the initial radius was smaller, the caustic would be sharper from the start, but image would be noiser overall.
Instead of basing it on the world bounding box, I perhaps should base it on bounding box of the photon map. But in this case it's exactly the same.
Photons per pass means how many photons it shoots between ray tracing passes. It doesn't store photons for the first hit, because direct ligting is computed like in regular path tracer.
This is also kind of a tradeoff. In scenes where there is no direct ligting (emitter is not directly visible by the diffuse surfaces) all direct lighting computations (visibility checks mostly) are a waste of time. But in the other case, when surfaces are lit directly, those direct lighting computations helps quite a lot.
And an alpha parameter controls how fast the initial radius shrinks.
Here I attach my 45m render (mobile i7):
