
SIGGRAPH 2009 Realtime GPU Raytracing Demo - jawngee
http://www.cgarchitect.com/news/SIGGRAPH-2009-CHAOS-GROUP-GPU.shtml
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pmorici
Not really that impressive, esp. compared to the product offered by Caustic
graphics that has been posted here before, <http://www.caustic.com/> they do
realtime ray tracing with a piece of hard ware a kin to a graphics card that
fits in a desktop.

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manvsmachine
Except that the total cost of investment is a $350 piece of commodity hardware
and a free/open SDK. If it's not fast enough, just throw in more / faster
cards. Using Caustic's platform means putting min. $4K into a unproven
proprietary platform. If performance/price didn't matter, you might as well
say "Not that impressive, considering you can just build a render farm".

No disrepect to Caustic, but I could easily see them going the way of Ageia if
they're not careful.

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pmorici
I see your point but is the target audience for this technology using $350
commodity cards to begin with? High end Nvidia Quadros cost in the range of
$4,000. This CUDA solution looks like it provides less impressive results and
I don't think a video production company is going to sacrifice image quality
to save a buck. If this were targeted toward Joe average consumer than I agree
with you.

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manvsmachine
I think you're somewhat misunderstanding the role that CUDA plays in all of
this. You wouldn't need Quadros because the CUDA cards would only need to be
responsible for performing the raytracing calculations, not actually rendering
the image (unless you want it to). So they could have had 4xGTX295's,
equivalent to 8 of the boards used in that presentation, just crunching
numbers and then one workstation-class card to render textures, etc if they
were concerned about render quality. If someone was still concerned about
using GeForce cards, Tesla C1060's still cost only about $1K a board IIRC, and
I think they'd be _way_ faster at this sort of thing than the GTX285 used.

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trapper
I'm surprised this field hasn't moved forward as much as I thought. If memory
serves me correctly, I remember being shown a cuda based real time ray tracer,
with similar limitations by a masters student in early 2007. They ran into
lot's of troubles because of the architecture of cuda itself (e.g. maximum
occupancy was never very high on average), but could produce stunning realtime
visuals at low framerate (e.g. 640x480). Not different from these guys at all.
At higher resolutions it was much, much harder as the solutions didn't scale
because of the limitations of cuda.

I expected to see him presenting his stuff at siggraph but never did - not
sure what happened to him, and an internet search reveals nothing.

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nailer
This seems somewhat less impressive that the raytraced Quake 3 from a few
years ago, which has a higher framerate, less on-screen artifacts, and is also
a well known application.

<http://www.youtube.com/watch?v=bpNZt3yDXno>

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jawngee
Except this demo isn't rendered on a farm like the quake demo is, plus does
caustics, global illumination and is more suitable for professional
application than the quake demo is.

