Best GI Tool (Global Illumination)

[Marcel]

Lately I prefer using just the scanline renderer. Most of the time I use a skydome to fake the GI.

I just got sick of the stupendously long rendertimes, that is, if it was even possible to use GI for animations. (Because of the dreaded flickering of the GI)

It's all very pretty, but when my testrenders take 15 minutes I do not have enough feedback to work properly.

I hope that in a year or two computers will be fast enough to really use it without having to wait an eternity.

[toonman]

The BEST GI engine? Isn't that a bit hard to define? From my POV, the BEST GI engine would be the fastest, most efficient (resource-wise) one. This would require us to know a bit more about rendering and GI algorythms that most of us know (throw in some physics and optics in there). I particularly use mental ray, but not because of the GI. There are a big deal of advantages to it besides GI/FG. Cheers!!

[ToddD]

Hi Anton Andriesh, I'm far from a pro, but I would say if you learn more about properly lighting a scene, you won't even need GI. I've seen some outstanding scenes that were just well lit with the basic lights given to you in max. A while back I rendered something in brazil with an array of lights, it was virtually identical to a much longer GI render. If speed is a concern, ditch the GI, unless of course you have a blazingly fast PC.:beer: :)

[Chico]

yea Im with Tbonz816,

GI plugins may be getting faster but you cant beat the speed of a well lit scence..It doesnt take ong to get a basic setup, and it takes even less time t orender them.

MAX ONLY.!

[Anton Andriesh]

Thank you for replies!

I was using max's illumination for a long time with finalRender for some advanced effects such as soft shadows and readiosity.

But after seeing finalRender's GI I think that there is no reason to use max standard illumination for this. The only problem is rendering time...

That's why I'm asking here if someone had to use other GI systems and can compare them with finalRender's GI.

:beer:

[kandyman]

Vray is very nice - is use it exclusively these days, even for non-GI renders.

marin

[Grayson]

I must admit I'm with Tbonz816 too.
These are just some tests I've been playing with. It renders in under 24 secs, including render time this scene took only about 2 hours of work.
It's not perfect, but for 24 secs, it's good enought for me. :)
http://grayson.cgworks.com/img_drop/gi-fake.jpg

http://grayson.cgworks.com/img_drop/fake-gi-divx.avi

[datter]

I've experimented with a few (Vray, FR, MR etc) and find of the bunch Vray is the fastest with FR being second but more configurable.

If I had to pick one I'd choose VRAY as it's the fastest I've seen and the easiest to use. The "GI crowd" gripe about how it's fast because it's "less accurate" but who cares, the results look great to me.

Still, I'd rather pass on GI altogether and fake it where needed.

datter

[fred_bock]

I'm using final render now ... it's quite cool, but i don't know how to use it very well what makes me a little confused about the question of use it or not ... i hope to know how to take advantage of this engine pretty soon ... any help about this quest is apreciated !!:beer: :beer: :beer: :beer:

[wizard]

hey yeah i noticed that flickering too in GI thats bad i mean how can you be sure if your final animation is going to flicker or not in places. after hours of waiting is there a solution by the way.. :bounce:

[-JT-]

Vray because it's easy and fast. I look forward to trying max 5's gi.

[Ed Lee]

I think the originator of this thread was asking for quality..dunno. Having tried few GI plug-ins (fR, Brazil, Vray...Entropy) I have to say Vray prb has the quality u look for in Brazil and the speed of fR. I would like to try Arnold, tho the demo is not available. Well, Arnold pretty much started the GI hype in Max...or at least made it popular. I prefer Arnold for quality, and Vray for speed, $$ and ease of use.

Ed--

www.edleeart.com (http://www.edleeart.com)

[GlasS-]

Well, i dont know how to fake GI so i guess i need some help with this.. I think knowing how to properly light a scene by yourself must be better, but since i dont know that much about lighting a scene, its kind of hard for me :/
Although, i really want to learn faking GI, i just dont know where to begin.. If you could give me a hand, ill be a happy guy ;)

[ilasolomon]

Anton Andriesh, you forgot to ask for these too!:
BMRT, Entropy, Vray, Insight, AIR, Mistique, Arnold, VLight
all have GI solution!

[datter]

Maybe I can write a tutorial about faking GI for my site, but in the meantime here's a short 'how I do it' and please remember a) there are always other and possibly better ways to do things, and b) I'm tired so ignore any typos. ;) Also, please forgive me if I start hashing over the obvious here... I'll likely use this text for the tutorial in some fashion to save the typing. hehheh

The first thing I always do when lighting a scene is consider what environment conditions I'm trying to replicate. Interior fluorescents (which tend to be greenish or bluish in the tone given off), interior sodium or standard light bulb (which can vary but tend to be warmer in the yellow range), exterior sunlight (higher contrast and towards yellowish), exterior overcast (low contrast, little shadow, if anything a slight bluish cast) etc etc.

Once I have the main light source I want picked out its a matter of how to replicate that in the scene at hand. Studio lighting (as for a photo shoot) often involves at a minimum three lights. The key light (the main illumination source and is usually high and to the left or right of the camera), the fill light (which is in the opposite angle of the key light and is used to lighten up the dark shadows caused by the key light) and the rim light (which is often level with the subject of slightly high, and always behind in order to provide an edge of light on the profile of the subject... i.e.- backlighting). There are a myriad of other lights and placement that can be used, but this usually a minimum for good studio lighting. This same set up can be used effectively in 3d renderings as well though often with more fill lights to lighten up the shadows, or with the shadow density turned down.

Global Illumination takes lighting a step farther in that it not only simulates the light sources themselves but the reflected light from those sources. Now if you put a sphere on a plane in a 3d app and light it with one light you'll get a very harsh image with one side lit up nicely and the opposite side in dark shadow, with GI the app will calculate the light that bounces off the plane and back onto the sphere (and vice versa) to give more even, realistic lighting.

So how do we simulate that in 3d without having to use real global illumination? One effective technique I use is called ring lighting (that's what I call it anyway). With this technique I place one omni light to the left and above my scene. It's colored as per the info above to reproduce whatever light source I need and set at an intensity of .3 or so with shadow casting turned on (shadow maps). I then copy this omni light to the other side of my scene, and then select both lights. From there I shift-rotate these two lights, which now pivot around the center of the scene and copy them over 8 to 10 times which provides a circular array of lights. I then select all of the lights and move them above the scene, if they're not already there. A lot of times this in itself will provide some nice GI like lighting, at least at a glance but there's a few more things to do to complete the effect.

After doing a quick test render I get a feel for how the light affects the scene. Often I'll have to tweak three or four lights on one side of the ring to increase their intensity a bit, in order to give the impression of a light source. This has the effect of lightening one side of the scene a bit and creating a bit more shadows on the opposite side, while still retaining the relatively even lighting the ring provides. It's also a good idea to tweak the ring to provide for some variance in the colors of each light. For example you might want to put yellowish tones on the side where the main light source is supposed to be, and bluish tones on the other. Another useful thing to do is to slant the ring so it's not level with the ground plane, usually placing the brighter edge up a little higher.

Since GI also accounts for the reflected light, we have to as well. You can do this in a couple of ways. The first may or may not work out depending on the scene but lowering the density of the shadows the ring of lights creates can give the effect of reflected light by brightening up the shadow area. The other option is to grab some lights from around the ring (3 or 4) and copy them down below your scene. You'll have to exclude the ground plane so the lights will affect the objects in your scene and you might want to turn off shadow casting. Now, by setting these lights to low intensities you can essentially fill in the shadow areas as needed. You might also pay attention to the color of the light in that if you're simulating light reflecting off an orange floor the lower set of lights will need to be orange in color.

That's a good overview of how I go about it, you may or may not find a better means but this is what works for me.

One last thing I'd like to mention is that in simulating GI you’re really simulating actual light, as it exists in the real world. As such I'd really recommend you start taking notice of the way light works in your every day life. Try and pick out different colors in a rooms lighting, and try to see how the side of your TV set is lit with light reflected form your wall etc. If you make it a habit of noticing and studying real world lighting as you find it you'll soon find yourself thinking about how you could reproduce it in 3d. The more you think that way, the more you'll experiment and find a solution that works well for you.

Hope this helps a bit, sorry for the novel.

datter

[Anton Andriesh]

Hi Grayson, you have a good illumination in you scene.

But I think not all you can do without GI. If someone could show me a method of how to render something like what's on the image, I would be very happy to uninstall my fR, or simply not to use it for GI.

Here's the the image:

[yair]

faking gi from some web friends. the second one is for natural lighting and not gi but it has some good clues for lighitng with sunlight anywayz

http://www.michaelscholz.de/neuehomepage/tutorial/tut01_e.html

http://www.michaelscholz.de/neuehomepage/frames_englisch.html

i had another one but its gone.
go to scriptspot.com for a number of very good and fast..er gi faker

[Wiro]

I'll probably step on some toes here but I'm really convinced that GI is better than any manually setup lighting system. The GI rendering may yet be slow but with increasing CPU power and better coding this will improve.

I don't aggree that traditional lighting methods are good enough to fake GI. I almost always notice traditional lighting in film effects because parts seem to float due to lack of very soft shadows. It's very evident in dusk or indoor scenes with no direct light.
I've yet to see a scene that wouldn't look even better with GI.

As for the original question; I use finalRender

Wiro

[visualboo]

Wiro.... I agree 100% bud.

Vray for test renders (very fast)..... then Brazil all the way for final tweaking. I just cant seem to get the same quality out of vray as I do with brazil.

[JuRrAsStOiL]

*seconds-Wiro*

I can just agree, GI is still very slow, but with a bit tweaking
on the engines (fR Stage-1 :drool: ) I hope that GI becomes
standard. The lighting process is much faster and of course
more accurate. Sometimes you need some extra omni-lights
to get an almost real GI look with finalRender, Brazil or VRay.
This got something to do with the infinite diffuse bounces in
reality. You can't do this with fR (this would render for 1.000.000
years :D) so sometimes I use extra omnis or the cool fR
Lighttypes like RectLight or CylLight. I'm just using fR, I think
it's much easier to control and to adjust then VRay or Brazil.
And of course it's FASTER! You can do lowRay (perhaps a new
scene-word :D) REnderings with just 8 Rays or so and you
get an impression of what the final image will look like.
Then you can increase adap. quality, the Prepass size and
the Rays. finalRender finalRender finalRender finalRender
finalRender !

@Wiro, any information on fR-Stage1 release date ;)

I don't do any scene with out GI or fR, it just feels
like standardly integrated :D

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