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Member Since 10 Mar 2004
Offline Last Active Feb 20 2016 04:44 AM

Posts I've Made

In Topic: Arauna2 path tracer announcement

14 November 2013 - 04:54 AM

For those with fast GPUs, here's an executable that renders at full 1280x800 res, instead of the upsampled 640x400:


Note that this requires the original package for the data. Also note that this still uses only one GPU; multi-GPU rendering has been disabled in the demo.

Let me know how this runs on your machine. :)

In Topic: Arauna2 path tracer announcement

13 November 2013 - 06:06 AM

Really nice demo. Wish I could try it out (AMD here). I'm curious, are you planning on porting the code to OpenCL anytime soon or is it too deeply integrated with the CUDA platform? Also, how do the lens effects work, for instance, at the beginning of the video? Are they path-traced as well, with the optical system part of the geometry, or are they a post-processing step?


OpenCL support is highly desirable, and should be available at some point in time. That, or a generic alternative. A CPU tracer is already available (not in the demo); it produces the same output, but a lot slower (it was not built with CPU performance in mind, but with a focus on maintainability).


The post processing (hit F3 in the demo, it's off by default) is just your typical image post processing. The lensflare is pretty accurate; it's based on recent work by Prof. Eisseman of the Delft university. It does a pretty close approximation of physically correct lens flares.

In Topic: Arauna2 path tracer announcement

13 November 2013 - 04:35 AM

Have you or will you plan to implement any type of noise filtering?


Filtering is being researched at the moment (not by me though); it is far from trivial in this context. Normally you would do something in screen space, but a path tracer typically doesn't have a single depth per pixel (which is needed to find geometry edges), so that is of limited use. The best solutions so far filter in 'path space' (considering the full set of paths arriving at the camera), but this is compute- and memory intensive.


I would expect filtering to bring a significant improvement to path tracing at some point in time, but right now, it is not yet sufficiently researched.

In Topic: Ray Tracing Blog & Forum

23 May 2013 - 11:16 AM

Didn't the header use to say "temporary replacement"? I guess it was about time we faced the cold hard truth sad.png


I like the blog initiative. Want to see more smile.png


Yeah, sad story I am afraid, tbp disappeared, but he left a vivid community. Sadly we couldn't even salvage the old board. It was such a unique place, with an awesome blend of academics and hobbyists (and people slowly making the transition, like myself). The new board is similar, but tbp was a far better board operator. I wish I knew where he is now, he disappeared.

In Topic: Anyone here a self-taught graphics programmer?

23 May 2013 - 11:09 AM

Hm, I see a lot of familiar stories. Mine, briefly:

Got a zx-81 when I was 12, and overjoyed with it. Copied code from books and magazines, learned English that way. smile.png Then my grandpa bought me an MSX, which I really enjoyed; coded it on the assembler level. Got a game published as source code in a magazine when I was 16 or so. Then I got an Amiga, played games, no coding... Hated the thing. AMOS did work for me, but only slightly, because it was way too slow. Then I got a PC, and I used it like the MSX: Turbo Pascal with inline assembly, and finally sufficient performance for decent 3D (which I got interested in by a source in an MSX book that did some basic 3D). I spread my code using BBS'es, still no internet...

After that: software rasterization, at a very decent level; maybe someone remembers the Alpha engine, and Focus. Then the GPU arrived, which I managed to evade, because I didn't like the 'canned polygons'.. When shaders arrived I got a bit more interested, but in the meantime I discovered ray tracing, and the impossible performance claims made by Ingo Wald (realtime!). After a few years, I got to that level, which was incredibly rewarding; I got there by reading tons and tons of papers. 6 years later, I got my PhD basically on the side, topic was real-time ray tracing for games. smile.png Very proud of that.

In terms of education: none related; MSX time was books-only (from the library, mostly), PC time was books only too, plus some stuff from BBS'es. Then came the internet, which was amazing: I wrote the portal column for flipcode, and later a similar series on ray tracing. Obviously, I got tons back as well. After that I got my stuff from papers, which currently still is my main source of information. I did most of this in solitude, I think there was only one guy that really thaught me a few things (besides book authors, such as Michael Abrash).

Times have changed though: you can now actually get a decent education in games and graphics, which at least allows you to be around people with similar interests. Even if you can't do such a course, you will still be able to meet those people online, which makes a lot of difference. On the other hand, the amount of material to soak up is just incredible, far more than when I started, and I can totally imagine that this is daunting, to say the least. When I got into this, at least it was possible to know 'everything' about graphics (getting close to Abrash, Wald, Fatmap and Fatmap II). Right now, you either pick a niche, or you become a generalist in a narrow field.

Now I need to get back to adding spotlights to my path tracer. Graphics programming is such a joy!


- Jacco.