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Coherent MLT with Multiple-Try Mutations
Posted: Sun Sep 23, 2007 2:58 pm
by CoolColJ
paper of interest
We accelerate the Metropolis Light Transport algorithm by adding a new class of Multiple-Try coherent
mutations. With these mutations, we are now able to use ray packets or ray packet frustums to speed up the intersections and
the BRDF evaluations.
http://bat710.univ-lyon1.fr/~bsegovia/p ... f/cmlt.pdf
Posted: Sun Sep 23, 2007 3:19 pm
by zsouthboy
This is an obvious extension of MLT
Nice find though.
Posted: Sun Sep 23, 2007 3:35 pm
by CoolColJ
the speed difference is pretty amazing!
1-2 million mutations a second! That's what Ian got with a monster 3 PC network in a recent test
We are taking about finished renders in under 2 hours tops at that speed!
Posted: Mon Sep 24, 2007 12:55 am
by vux
what Ono think about this paper?
is it real in Indigo in future???
Posted: Mon Sep 24, 2007 6:20 am
by StompinTom
sounds too good to be true... the examples at the bottom of the paper were each rendered for 5 minutes on a single dual-core machine and look great! i didnt see any caustics examples or very tricky light situations so im a bit curious to see how it would handle stuff like that...
IMO worth looking into, but im no coder.
Posted: Mon Sep 24, 2007 6:43 am
by Kram1032
If I understood that paper correctly, (as far as I understood it), they stole MY idea, before I had any chance to make it reality

xD - the second "MY" idea, today xD
Posted: Mon Sep 24, 2007 9:37 am
by CoolColJ
If Indigo implemented this then you can rule the universe with a quad core
Wow, brute force MLT rendering that can match and beat current GI renderers for speed and accuracy!
Posted: Mon Sep 24, 2007 9:57 am
by Anthony
Even if it is a bit screwy, which I hope it isn't, it would still be great for preview material renders and quick tests and stuff

yaCORT
Posted: Mon Sep 24, 2007 10:47 am
by Knaxknarke
This is from the same guy as the GPL OpenRT realtime raytracer yaCORT:
http://liris.cnrs.fr/~bsegovia/yacort/.
The pix from the paper are also on the yaCORT gallery, so it seems it was made with this rtrt framework. Would be interesting if the coherent MLT code is in the GPL version or if it's made with an research/prototype branch.
Never used it, but will test it soon now. It's for the Linux freaks out there: no Windows version available right now...
Posted: Mon Sep 24, 2007 11:21 am
by Anthony
Omg realtime? I wonder how it will run on the ps3? Hopefully soon we will be playing games with realtime caustics...
Posted: Mon Sep 24, 2007 11:25 am
by CoolColJ
have a look at his other papers at the bottom
http://bat710.univ-lyon1.fr/~bsegovia/
Posted: Mon Sep 24, 2007 8:05 pm
by vux
Posted: Thu Oct 25, 2007 2:06 pm
by bouliiii
Hello there,
I am the one who coded this stuff. I don't know if it will be finally accepted (resubmitted) but I think it is a simple and not-so-bad idea. In fact, the first goal is not really to use SIMD (even if Larabee, the upcoming Intel processor will have 512 bits wide SIMD instructions ! (16 x float ....) --> imagine the speedup!) but to factorize all cache accesses (typically for displaced geometry for example).
Numerically, the behavior is almost the same than MLT. The mutations are just reordered. As for the integration in an existing and *real* renderer (I mean with many features like indigo, not a small code like yaCORT) and the use of vectorized data and instructions, I think it may be a huge task.
However, factorized cache accesses remain really interesting for inhomogenous processors like Cell (I implemented a SIMD raytracer on my PS3 and with a cache the speed up was superior to 20 compared to a scalar approach!) and certainly like many future processors.
Ben
Posted: Thu Oct 25, 2007 8:30 pm
by Vanessa07
Code: Select all
ENTPE: Ecole Nationale des Travaux Publics de l’Etat, Vaulx-en-Velin
I know that school, they work with 3ds and maxwell...
here an offer employment, if somebody wants to work in France, it's 2400 euros/month
http://www.anpe.fr/espacecandidat/nicol ... ce=951567C
Posted: Fri Oct 26, 2007 5:00 am
by Slobodan
Very Impressiv work Ben....
It would be nice to see this in Indigo....