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cavalos
04-16-2003, 05:53 PM
This one is for NT development team or any with experience on GI solutions. Ok I know there are different solutions for GI so what is the best for the next generation of Lightwave Radiosity Engine.

1) Full Cuasi Montecarlo
2) Montecarlo Path Tracer
3) Irradiance Maps
4) Photon Mapping
5) Arnold "Brute Force" method

There is a good link in CGTalk that talks about "wich is the fastest GI renderer"

http://www.cgtalk.com/showthread.php?threadid=50228

also take a look at the link of thi guy too

Hi,
I've just completed my fastest test render so far, using my very own renderer. I'm extremely pleased with the high quality and resolution I was able to achieve due to my superior choice of algorithm (Monte Carlo path tracing). Most impressive of all is the render time - only 24 hours and 5 minutes!
http://www.graphics.cornell.edu/~ajb64/
I hope to see this algorithm used more frequently in commercial renders, instead of the slow and poor-quality photon mapping (which produces a biased solution anyway!)

harhar
04-17-2003, 01:04 PM
No one even knows what the Arnold method is. There is no way to implement it unless arnold make it public.

And since mental ray and brazil all use photon mapping, I doubt he can convince people otherwise.

Panikos
04-17-2003, 02:19 PM
There is some info on the net about Arnold and several pics.
I also found a Siggraph Paper in which Marcos Fajardo presents Arnold.

Here is some info :
Unbiased MC: path tracing
Fool-proof: only one quality knob to tweak, the only artifact is noise
Spends most resources in visible features
BRDF importance sampling
Fixed path length, not truly unbiased. 2 bounces are usually enough
Next event estimation, can be turned on and off on a per-light basis

Sampling
Improved convergence by QMC (low discrepancy sampling)
Low discrepancy sampling avoids random selection of samples
Randomized QMC avoids aliasing (Cranley-Patterson1976, Owen1995)
ARNOLD uses RQMC (since 1999)

Geometric complexity
Efficient storage of dense triangle meshes
Fast ray traversal of dense triangle meshes (almost constant time)
Hierarchy of nested uniform grids
Grid preprocessing time is a tiny fraction of total rendering time
Geometry must reside in memory at all times

Shading complexity
Shading is decoupled from geometry
Arbitrary parametric BRDF’s
Any BRDF parameter can be fed with a texture map or procedure
Atmospheric scattering and procedural volume shaders

Light sources
Standard types: point, spot, spherical, quadrilateral
Any geometric primitive can emit light
Why skylight works”
– The sky is hard to miss with BRDF sampling
– Rays don’t bounce off the sky
– Performance degrades as we move indoors
HDRI-based lighting. Spiky light probes are hard to sample

Parallelism
Split the image into square, independent buckets
Shared memory, multi-threaded bucket rendering.
Bucket or frame granularity in network rendering
Animation
No artifacts: fully compute every pixel of every frame
No preprocessing
Motion blur comes for free (almost)

harhar
04-17-2003, 04:48 PM
you can see arnold in action by purchase PmG's Messiah: Render.

Elmar Moelzer
04-18-2003, 05:19 AM
Hello
I was talking to a few Messiah- Studio- users a while back and they said that Arnold is still pretty much unusable. Dont know whether they fixed it meanwhile...
CU
Elmar

pixelmonk
04-18-2003, 06:16 AM
Originally posted by harhar
you can see arnold in action by purchase PmG's Messiah: Render.

That's not Arnold. They purchased an early Alpha Arnold from the developer and developed their own from there.

harhar
04-18-2003, 05:32 PM
ha ha, arnold is still in early alpha, so it's arnold.

cavalos
04-22-2003, 05:00 PM
I don´t know any Arnol or messiah users to date but acording to some beta testers Arnold is the fastest GI renderer and there are other GI renderers wich might be even faster than Arnold (Dali renderer) for example.
Shure things can be faster in LW GI solution but the only problem is to find a balance between quality and speed don´t you think?

Best
Christian

fyffe
05-10-2003, 08:12 PM
Okay, for a real GI renderer, you're going to use all four of these:

1) Full Cuasi Montecarlo
2) Montecarlo Path Tracer
3) Irradiance Maps
4) Photon Mapping

Plus some other stuff. You want to have a quasi-monte-carlo path tracer that uses both irradiance maps AND photon mapping to help with the sampling. That's just the TIP of the iceberg. Nearly every reasonable renderer has all these features, and these features are not what separates the super-slick from the run-of-the-mill.

- Graham Fyffe

amorano
05-10-2003, 11:09 PM
Or you could do 2 other things....

A) Don't use GI at all, since even the big guys don't. Look to Ambient Occulsion for how/why ILM does this.

B) Use bounce lights.

I have found that smaller farms (like the solo or under twenty machine shop) don't even look at GI as a solution, esp. when other lighting methods have been in use for a decade+ that produce equal results in tenths of the time.

I feel that things like GI still scream Uber-I-Think-It-Will-Make-Pretty-Method. If your worth your salt these things can be done sans bleeding edge feature.

marko
05-11-2003, 08:18 AM
A) Don't use GI at all, since even the big guys don't. Look to Ambient Occulsion for how/why ILM does this.

3. paint GI in photoshop ;)

Panikos
05-11-2003, 08:27 AM
With such thoughts, we would have been still in quickshade rendering.

I believe that its a matter of time and patience for better GI renderings.

cresshead
05-11-2003, 10:30 AM
there are big disadvantges to othe GI methods compared to lw's..final render is very fast BUT it's view dependant..that's why it's fast...you have to "sample" frames in your animation the renderout...but you may still have flickering and texture crawling etc...it's pretty good for stills but not as nice as lightwave...that was one of the main reasons i bought lightwave as my second 3d app...i wanted a top renderer...i already had max scanline and final render...lightwave is really nice...don't knowck it so much!...brazil is okay but at the same price as lightwave i went for a full 3d app rather than another renderer for max.

mental ray is a good move for maya but remember you only get one node to render to..other will need paying for!...same with brazil to a extent [4 nodes]

steve g

amorano
05-11-2003, 01:25 PM
Originally posted by Panikos
With such thoughts, we would have been still in quickshade rendering.

I believe that its a matter of time and patience for better GI renderings.

Sure, if you are three years old and can not find alternative solutions to problems.

I am all for magic buttons when they are magic. Radiosity in LW is far far far from magic. Just the fact that I can not animate with it without it crawling and(more AND than or)/or it taking super long render times.

Why would I want this solution in a production pipeline, since most industry big boys do not touch it with a ten foot pole, having better served the end vision with alternative techniques?

Please, do not think out side the box, because, when and if more people do, this industry will be even more overcrowded with little jons and janes who know where the magic buttons are but not what they mean.

amorano
05-11-2003, 01:34 PM
Originally posted by cresshead
don't knowck it so much!...brazil is okay but at the same price as lightwave i went for a full 3d app rather than another renderer for max.



Vray and Mantra are also good. Lets not forget PRM. Which as of 11 can do GI.



mental ray is a good move for maya but remember you only get one node to render to..other will need paying for!...same with brazil to a extent [4 nodes]



Not only that, but if you want access to higher end features, HDRI for instance, you still need a copy of standalone Mentalray. Then things like FUR and Paint Effects are not supported in Mentalray. I am sure they will have it figured out soon enough though. And the ubiquitous no support for Macintosh currrently.

marko
05-11-2003, 02:15 PM
i think computers are here to give us magic butons (F10)

take look at vray tutorial ant their photon map solution.

http://www.vrayrender.com/stuff/PMapTutorial/

marko

harhar
05-11-2003, 06:10 PM
Prman's GI is like the slowest in the industry, mabey except mantra.

Maya's MR has pretty much all the high end features the standalone MR has, include HDRI rendering. PaintFX can be baked so it can be rendered in nay renderer. As for fur, there's shave and haircut.

No production houses will use Mac to render.

jin choung
05-12-2003, 01:00 AM
http://firingsquad.gamers.com/features/sweeney_interview/default.asp

http://graphics.stanford.edu/papers/envmap/

http://www.research.scea.com/gdc2003/spherical-harmonic-lighting.pdf

actually,

SPHERICAL HARMONIC REFLECTION MAPS may be a compelling solution!

it's a cheat that can be used for even RT purposes but if it's that freakin' fast and it provides results that are for most intents and purposes INDISCERNIBLE from true irradiance calculation, [email protected]#$ it, let's cheat!

i'm tellin' ya, RT and non RT 3d stuff is converging big-mofo-time these days.

jin

Emmanuel
05-12-2003, 07:29 AM
Well, I hope that 8 will have some of that really cool stuff that makes other apps go "hmmmmm..".
I think LW could afford a truly state-of-the-art preview in viewports, including realtime shadows, transparency/blending, bump, normal mapping, etc...