Nice lighting without FG or GI

[zaharidichev]

I was just wondering do you people think that the Maya mental ray Physical sun and sky is a good option for rendering outdoor scenes. I mean it gives good results but at the same time it just looks almost always the same and there is not a lot to tweak. On the top of it it uses FG which complicates the things even more.. I was just wondering do you know some tricks or rigs that can fake sunlight or give me a point to a decent more tweakable solution.I am not asking for a particular project of mine. I am just trying to gather as much info a s possibleand try a lot of techniques. BTW Is there a good was to actually represent daylight situation without FG. I was looking ot the Gnomonology light rig. It gives good results but the result is not what I need. I just want to know how it works and since they dont actually provide a breakdown PDF but just the rig I was hopping that someone here can give me a cople of tips on lightining without the use of simulated diffuse light such as GI and FG. Any help GREATLY appreciated

[Geek]

Hey,you can try path material.Another trick is to use colored Ambient ocllusion to replicate FG effect,but of course this approach is much cheaper(faster).There was a great lecture by a guy from Pixar,don't remember his name,but it was from Gnomon live event (previous or the last one).He shows some really great tricks to fake almost all the complex computational procedures like,GI,FG,light in participating media and SSS.I think you'll be able to find this lecture it's pretty awesome.

[zaharidichev]

Thank you a lot Geek. I was trying to find this video but unfortunatelly I couldnt... I am supporting my question with an example. Here are two images the first one is with FG turned on and the second is OFF. As you can see the firs result is much nicer. Any ideas on how to fake that without the use of FG. The other thing is that I cant figure out why are these spots occuring. Thi happen only when I am using area light for the windows WITH attached Physical light shader for them. Any ideas on my problems?
http://img32.imageshack.us/img32/3761/examplev.jpg

[Geek]

What about getting the same result as FG but withought FG :):well,FG just helps to destribute the light more accurately but you can still try to achieve this effect by placing additional light sources,it's more kind of artistic approach i guess.What about spots:i've faced with this,use oversampling node or invrease color contrast and if it doesn't help increase min/max sampling rates

[glxtrix]

Traditional lighting is always key when trying to fake FG. I typically use a ball of directional lights. For that pic, just start throwing some soft spot lights around the window to give it some spill.

[mmikee]

You can also try AO for the indirect.
What I do is.......

Create an IBL node. Then create an area light. Turn the shape to user and the samples to 1. Add an AO texture as a light shader. Change the mode in the AO from 0 to 1. This will cause it to get its color from the environment (the IBL). For the example posted above add a night image (or anything that you want) to the IBL. Then you can control the brightness of the AO with the bright (white) color swatch. I would assume you want want it very dim. This works the same for daylight setups.


Regards,
Mike

[daddyo]

If you don't want to use indirect lighting, you can achieve the missing lighting using a few well placed area or point lights... It doesn't look too tricky.

[Shimrod]

As additionnal lecture, Jeremy Birn (Pixar - CgTalk Lighting section moderator) explains the old traditionnal ways of lighting in his book. ;)

[Crispy4004]

Well, I have a solution. Below is a render of one of my models using *gasp*, no Final Gather. Not using any fancy light rigs or anything like that, just plan old Physical Sun & sky. It still is faking it to some degree, but the results are better and often render faster than other solutions I've seen.

Unfortunately it is a bit of a pain to setup because it requires some manual work for each material, but I'm helping Deex (http://forums.cgsociety.org/showthread.php?f=87&t=828928&page=1&pp=15) incorporate it into create his render pass script.

http://img690.imageshack.us/img690/1396/65125246.jpg