Progressive photon mapping with metropolis sampling

Hi again,

To answer my last entry, I've added metropolis sampler to my photon tracing routine.

Well it was a natural thing to do.

I am aware of that paper by Toshiya et al. - Robust Adaptive Photon Tracing using Photon Path Visibility.

But since I am quite familiar with Kelemen's mlt, and I didn't want to switch to that sppm approach (I keep it as a traditional photon mapper with shrinking radius), I implemented it quite differently. Path quality is equal to how many photons do contribute to photon map (and photon map's bouding box is based on the visible hitpoints). So it just favors longer paths. Perhaps I could extend it to how much flux the path carries.

Also like in standard Kelemen's mlt, there are 2 mutation strategies, small and large mutation, which the former needs some further testing like mutation approach and size.

So enough talking, pics:

Path tracing:

Photon mapping - random sampling:

and finally, Photon mapping - metropolis sampling:

All images were computed in 2 minutes, also the metropolis code is still fresh and messy.

I'm back

Yet again starting from scratch. Playing with metropolis.



Naive path tracing on the left, same thing but with metropolis on the right.

Multithreading and some GUI

Hi there,

I've added some multithreading and was playing with gui in swing.

As far as everything was a very pleasant experience, I'm concerned that
I got only ~190% load on my two cores, what means that the speedup is not exactly 2x.

So I've tested sunflowand noticed
that it also doesn't get anywhere near 200% - 180%-190% most likely. So I don't know...

Java path tracing

Hello I'm back.

My current weapon of choice is Java though.

The renderer supports:

• median split BVH,
• thin lens and pinhole camera models,
• sphere and Triangle primitives,
• naive path tracing with lambertian surfaces only,
• rendering in a progressive manner.

Performance is not that bad. I designed it to take full advantage of the new feature of java called Escape Analysis, so I'm not reusing objects (what leads to ugly code btw.) but creating them like crazy.

What sucks though is that there is no 1.6.0_14 java for Mac OS X yet, but I've tested in on windows and it works very well.

Some first, naive path tracing, renderings: