3D Projects: Lighting for CG Models

[DatterBoy]

BRIAN was kind enough to help me out with a bit of lighting on my CG Valk after I asked him about the lighting he uses on his models. He has some of the softest lighting I've seen to date that really brings out a smooth effect for his models and I really wanted to try it for myself. he pointed me to a MEL script for MAYA that I tried on my model and here was the effect:

I have to say I am completely astounded by the effect that lighting has on my piece. I was wondering if folks out there had any tips on lighting, effects, how to make a wing tip look "lit" as opposed to not lit, how to obtain certain effects (lasers, light behind the head visor) that they could tip me in on to make my Valk look more realistic.

To date,a ll the lighting I have is pretty much ambient light which tends to not effect the space around it and looks pretty flat, although it does stand out in the dark.

Thanks

:Dat

[mk16]

Well that looks nice, I suppose you used a fake global light dome. hmm I'm not much of a Maya user, but to get the effect of having something appear lit, you could make lets say a red material,or shader, with self illumination set to 100%, and then apply it to the section of the mesh you want "lit". thats pretty simple.

Lasers could be a long thin cylinder with another material , or shader whatever you wan to call it , set to 100 % illumination, maybe 50% transparent and have a glow attached to it.

Well I havent gotten the chance to play with maya yet. but i think those concepts should translate pretty easily to that environment.

As for your valk, i think the lightning is a little bright maybe tone it down just a tad. and if you put a plane bellow the valk, it should give it a little more depth. because it will catch the shadows cast by the valk..

Hope I've been of some help. well i know the techniques that i gave you sound kind of low tech. But its better

than nothing i guess.

Edited September 16, 2003 by mk16

[Brianw76]

I agree mk16, add a plane below the valk and tone down the light a little.

The lighting that I use is called IBL (image based lighting). It basiclly maps an image onto a sphere that surrounds the object and produces colored lights based on that image. Its exactly the same as the mel script except for the image mapping.

The image used for the IBL render below was of this battle pod

Note the new textures and rebuilding i've been doing since last friday.

[DatterBoy]

MK16:

Yeah, I used the global lighting from a MEL script Brian directed me to. I know I have a lot of experimenting to do with the lighting since I do not yet fully undertsand the concepts and mechanics behind it lal, but even with my limited knowledge I can tell that it;s much better than what I was doing before. I wanted to put a plane beneath it but I wasn't sure how that would play out in the end and figured a box would be better, but I would definitely give that a try. I am going for the "toy" look because that is what I intended originally. The brightness is giving me a hard time. I'll definitely tone that down a bit as well.

BRIAN:

Still not sure how how to tweak the lighting so I can get it to lok as natural as yours, but you're definitely the mark I'm trying to hit. Not duplicate, but that level of realism you seem to capture in your renders. Beautiful work on the valk. Still one fo the best I've seen.

And thanks again for pointing me to the script.

:Dat

[Brianw76]

hey Dat, if that script isn't working out for you you can get alot more lighting scripts at http://www.highend3d.com

I used to get scripts there all the time when i used maya.

[DatterBoy]

Why did you stop using MAYA?

[Brianw76]

I was way too slow with maya, I couldn't remember all the shortcuts. It took me days to do simple things. I'm still thinking about using it again, but only for animating the valk once its done.

[Doktor Gonzo]

Looks good guys. Brian, URL of that IBL/DRI script please?

[Brianw76]

here ya go doc. Global Illumination v1.1

[silentrage]

why not use mental ray for maya? :\ it comes with maya 5.0 B)

[Doktor Gonzo]

'cuz it's REALLY costly in terms of render time - easily an order-of-magnitude difference. I use MR for large still-renders and beauty shots, but try to shy away from it for animation. Hell, I try to avoid even using the Maya raytracer for animation, and there's nothing unorthodox in that - WETA Digital, for example, did a lot of hackworthy shader programming tricks so that they could render Gollum using raycasting, to avoid the render overhead of ray tracing. Mental Ray with all the trimmings is especially time-consumptive for animation, as the settings actually have to be turned up higher than they would be for single frames - techniques such as global illum., final gathering and caustic simulation are stochastic in nature - they produce realistcally real-world pseudorandom effects which have the nasty side effect of showing flicker/discontinuities across multiple frames. So to use these for animation, the settings (esp. # of photons) have to be turned up high enough to minimize the flicker. And that can take all day, all night and then some....

[silentrage]

you don't need FG, caustics and GI all at once, i find that a lot of people only need one element with the addition of environment mapping or some maya basic texturing at any given time,

and it's really not that time consuming if you're efficient with modelling and not building too much geometry where you don't need it.

besides you can use light groups for separate objects or objects/background and link # of photons or # of FG rays to distance to camera, this will save considerable amount of render time.

MR is more time consuming than other render algorithms but it's not that scary if you use it right.

btw, does anyone know if they used Vray to render M:0 or did they use something else?

[DatterBoy]

Damn, I'm such a CG Newb... all this lingo flying back and forth is way outta my league...

[Doktor Gonzo]

It's not a question of scariness or modeling skill, it's simply a question of using the right tool for the right job. For a single image, you can afford to render it "to the nines" and make it look as best as possible. But in a production environment, as I'm sure you know, one must always balance quality against performance. Using more renderer features than are required for the type of scene you're looking to generate could mean the difference between making a deadline and blowing it - consequently, knowing how to get "the most with the least" is in my opinion a good skill to cultivate....

[DatterBoy]

Another one, with a plane to cast shadow, but this time the shadow did not come out with definition, taking away from the realism.

DOK:

How do you do a fully rendered movie? To date, I can only get preview renders like screen shot movie grabs from the actual program. Could not find the optinon to render out a hi rez movie.

:Dat

[silentrage]

It's not a question of scariness or modeling skill, it's simply a question of using the right tool for the right job.  For a single image, you can afford to render it "to the nines" and make it look as best as possible.  But in a production environment, as I'm sure you know, one must always balance quality against performance.  Using more renderer features than are required for the type of scene you're looking to generate could mean the difference between making a deadline and blowing it - consequently, knowing how to get "the most with the least" is in my opinion a good skill to cultivate....

efficient modelling and linking camera distance to render quality and some of the other tricks ARE skills you know. B)

from my experience with MR you can get very nice looking results with low settings and render time is not significantly longer than Maya,i think you just need to find the balance there.

i mean I tried some methods like arraying a dozen lights in close proximity to each other and have them act as one light source, and arraying 48-64 low intensity directional lights to fake GI, but MR with low quality settings is actually faster and about the same quality.

I don't know about how it works with high resolution high quality productions though... havn't done one yet :\

do you have any rendered animation i can check out?

and just how bad is the flickering you descriped?

I learned that flickering in maya is often produced by the texture and you can get rid of it simply by tuning the pre-filter on the file node and be careful with using specular.

and uh datterboy, with maya you go to the render globals and set the format to either IFF or AVI and set the render range, camera, etc. then go render/batch render.

you can still use the interface while rendering, so you can work on another scene or something/

but you'll need to set a ram usage limit , and lots and lots of ram.

you can playback IFF sequences with the maya Fcheck.

Edited September 16, 2003 by silentrage

[DatterBoy]

SILENTRAGE:

Thanks!

:Dat

[mk16]

Ahhh, thats too bad, about the plane. well i think the problem is due to the nature of fake radiosity.

This is what should have happened .

http://www.splutterfish.com/sf/spluttergal...ery/pics/28.jpg

The image was rendered using a true GI renderer, for 3ds max. But it should be the same in any other software.

You could remedy the problem by putting a couple couple of spotlights (Four should do) around the valk. pointiong down at it. I think they would add to the image brightness, so lower the lights intensity. hmm But the new shadows could interfere with tthe softness of the valk. Hmm this could get complicated.

Something that should interest all of us

http://www.splutterfish.com/sf/spluttergal...ry/pics/117.jpg

Edited September 17, 2003 by mk16

[silentrage]

correct me if i'm wrong but,

i think just about everyone who's textured a valk is clearly missing a point,

those panel lines that you see on the toy and in the tv series and movie, they're not supposed to be actually mapped onto the valk as colors. They're panel lines!!! If you're gonna put them on, at least put some rust or dirt or wear and tear along them so that they look like edges between metal panels instead of spray painted black lines.

[DatterBoy]

You're completely right. I initially tried to model the lines but decided it would be texturing hell so I am having to remove them in newer less detailed models. Any references to actual weathering we can use out there?

[silentrage]

i'd say the best way to put them on is bump or displacement mapping AND texturing the wear and dirt around them.

i don't have any reference handy but i can tell you the best reference is photos of planes.

the common ones are oil or fuel streaks on and under the wings. Dirt and oil streaks under screws or bolts and the scratches on them. If a plane has to go as fast as the valkyries it's bound to get all kinds of streaks.

If i remember correctly the YF19's top speed with a fast pack is around mach 40.

(what the hell do they build these with, gundanium? )

there's usually dirt trails behind the windshield as well, from the dirt and rain water that accumulates in the rubber casing. And I notice that there are microscopic scratches all over the plane body, which only show up near the edges of speculars.

there's probably other kinds of wear, just get photo references.

oh yeah, don't model panel lines or scratches it's what texturing is for.

Edited September 17, 2003 by silentrage

[DatterBoy]

BRIAN:

Still experimenting. Some dark spots appear in the model, but I suspect it has a lot to do with the polygons as opposed to the lighting. Still don't achieve the ffect I am looking for, but I'm getting somewhere. Looks like a good "pearl" look so far...

I think I like the first attempt better. The shadows are slightly sharper. This version is waaaay too soft.

:Dat

Edited September 17, 2003 by DatterBoy

[EXO]

Hey Brian, hope you don't mind...

[Angel's Fury]

It's impressive that you guys can do that. I wish I could too?

[Brianw76]

Hey Brian, hope you don't mind...

haha, not at all.