scott <sco### [at] scottcom> wrote:
> An unbiased* global illumination ray tracer running in your web browser,
> with a max_trace_depth of 8 and support for shiny, diffuse, transparent
> and checkered spheres. What more do you want!
>
> Just run the attached html on a PC with a fast GPU, you can drag around
> the scene with your pointer. Inside the html file you can change the
> size of the image (right at the end of the file you'll see width and
> height tags), using non-power-of-two values may not work on your
> graphics card.
>
> You can get some pretty cool effects by looking through the glass ball
> into the mirrored ball.
>
> Disclaimer: It works on my machine (Chrome, Win7, nVidia GTX970) but
> I've not tested it on any other machine. Particularly if you have a much
> slower graphics card it may run so slowly that it crashes, or it may not
> run at all. Also make sure you have the latest graphics drivers, no I'm
> not just saying this it often makes a difference. The output should look
> similar to the attached image after a few seconds.
>
> ...
>
> After creating the standalone html5 page for blobs thread above, I
> realised it would allow me to do something shadertoy doesn't - that is,
> reuse results from a previous calculation in the next frame. I already
> had an attempt at a path-tracer in C# (which was in turn translated from
> some C++ code I found somewhere) but it was pretty slow. The main
> sticking point I had was learning how to render to texture using webGL.
> So it renders one "frame" at a time, which actually consists of 10
> samples per pixel, it then averages this with all the previous results.
> It then repeats until you move the viewpoint. The result is that once
> you stop dragging the scene around the noise should disappear eventually.
>
> Your browser will probably limit the speed of updates to 60 frames per
> second, so that equals 600 samples per second. You can increase the
> number of samples per frame on line 39. But I found if you make it too
> high that a single frame takes longer than a second or so the video
> driver crashes.
>
> * One of the hardest bits is to get a random number generator running on
> the GPU that is random enough to not show any patterns after a while.
> There is still some subtle non-randomness visible, but it's way better
> than it was originally. That's why there's random bits of code like
> rng.x = sin(r1 - FrameNumber) in there. It seems to do the job.


I got a "Could not initialize WebGL" message. with a quadro FX3800

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