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GPU-powered path tracing, take two

4: Adsense

GPU-powered path tracing, take two This image was generated with my GPU. I added minimal texture support, for the floor plane, and as an environment map (basically, when a ray does not intersect any object, its direction vector is used to sample the environment map and that is used as an approximate lighting value). I was impressed at the convergence rate, the noise disappeared in literally less than ten seconds thanks to the radiance contribution from the entire environment map.

If you are wondering why the sky looks overexposed, it's because I was using a low dynamic range environment map (so it was necessary to sort of fake the high dynamic range by raising the color values to some exponent, making the sky look weird). With a proper HDR image this would not occur as the sun in the environment map would naturally have a high radiance contribution whereas the rest of the image would have "standard" contributions, which would work better.

But high-resolution HDR images are hard to find and I need to find a way to parse them as well. Perhaps for the next entry!

A HQ (2048x2048) version of this render is available in my Gallery album. Beware - it's 10MB large!

Jun 14 2012 06:51 PM
Nice :-)

You're really making me want to write another photon mapping engine....
Jun 14 2012 11:26 PM
Thanks Apoch Posted Image

I totally got HDR nailed down today, mostly thanks to the excellent free library Vampyre Imaging - but I won't make another entry so soon - quality over quantity (and I need a code rewrite anyway). Just as a teaser... the caustics I'm looking at right this moment are amazing Posted Image
Jun 19 2012 12:14 PM
Agreed, that looks nice!

Though I've never written a tracer, I've always wanted to. Will be watching and reading.
Jun 28 2012 06:14 AM
This looks totally awesome. At first I thought it's a real photo.

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