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IMI
05-13-2007, 09:21 AM
I was reading the interviews at SpinQuads and found the one with William "Proton" Vaughn.

I was wondering how one gets this kind of look - lighting, shadows, etc. in LW?
Link:

http://www.cgfocus.com/interview/story/58&page=3

It's the top picture, "Runner of Vile-Tis"

It looks like Area lighting, but I can't be sure. I can't tell if it has radiosity on either, due to the lack of color.

I just really love this lighting, but can't seem to get it. I can get close, but not quite.

prospector
05-13-2007, 09:33 AM
use overcaster...from Flay

IMI
05-13-2007, 09:53 AM
Thank you, I'll give that a try. :)

hrgiger
05-13-2007, 10:25 AM
It looks like your typical skydome render. You just make a large sphere surrounding the scene, flip the polygons inwards, make them luminous and use radiosity to render using the luminous polygons often in place of your typical lighting solution.

Fprime renders these exceddingly fast.

Exception
05-13-2007, 10:59 AM
It looks like your typical skydome render. You just make a large sphere surrounding the scene, flip the polygons inwards, make them luminous and use radiosity to render using the luminous polygons often in place of your typical lighting solution.

Fprime renders these exceddingly fast.

Or, just a backdrop color of white with BG radiosity on. :)

IMI
05-13-2007, 11:09 AM
I can't use LW right now to experiment because I have it rendering and it will be for a couple hours, but I've never tried the sphere-with-luminous polys-and-radiosity thing before. Shadows will just "happen" as long as shadows are turned on? Shouldn't there be at least one light in there to cast shadows?
I'm not sure how it works - I've made luminous objects as part of a contributing factor for the light in a render before, but never as the sole source.

hrgiger
05-13-2007, 11:12 AM
If you turn on shadows, you will get shadows with luminous polys. However, they will be very soft since the light is coming from all directions, but that might be what you want. It doesn't matter if the light is coming from lights or polys, they work the same. And yes, as exception said you can just put a white background on but the reason I use polys is so I can make the light stronger on one side or the other by changing surfaes on the poygons.

Lightwolf
05-13-2007, 11:16 AM
Shadows will just "happen" as long as shadows are turned on?
They don't even need to be on... unless you want to see the shadows of LW lights.
Basically, shadows are the absence of light in the case of global illumination renders (and the real world).

Cheers,
Mike

IMI
05-13-2007, 11:28 AM
Thank you for the suggestions and explanations. :) I'm gonna try this as soon as I can, especially the idea of different surfaces on the sphere polys - great idea!

vsele
05-13-2007, 11:30 AM
Looking at the bluish color I think that is the Uffizi Probe hdr as Image world with backdrop radiosity activated....:thumbsup:

IMI
05-13-2007, 11:42 AM
Maybe Proton will come along and "shed some light" on this subject. :D

hrgiger
05-13-2007, 12:28 PM
They don't even need to be on... unless you want to see the shadows of LW lights.
Basically, shadows are the absence of light in the case of global illumination renders (and the real world).

Cheers,
Mike

I had not even considered it that way. I'll have to do a few test renders.

Andyjaggy
05-13-2007, 01:11 PM
with radiosity the shadows are just places that aren't getting as many 'light rays' so they end up darker. No need to have shadows on unless you want a light in the scene to cast a shadow.

hrgiger
05-13-2007, 01:19 PM
Ok, I did test it out. Mike is correct, having shadows enabled or disabled for luminous polys does not seem to make a difference. Enabling shadows for raycasting only appears to affect Light types. I never realized that before, I just assumed that shadows were global for all sources.

Here's a few tests I did to show you some different methods. The first one is a skydome all one surface. The model is receving light uniformly from all directions. The second render shows two different surfaces on the skydome, about 200% luminous on one side of the model and about 20% luminous everywhere else. And the third is showing a one surface skydome and then using it in conjunction with an area light. The third one is the only one where turning on shadows was required.

G M D THREE
05-13-2007, 03:15 PM
Surprised nobody is suggesting a occlusion shader. Its way faster then a sky-dome or BG radiosity. 9.2 has Occlusion || that lets you use a images as light probes.

///

IMI
05-13-2007, 03:17 PM
Hey, I want to thank you all for all the great info here that you've given me.
Attached here is a quickie experiment I just did, using hrgiger's suggestion of the flipped luminous sphere, with FPrime 3.
I just tossed in a few primitives, and my sphere (which was actually just a hemisphere, cut off below the 0 Y axis) had only one surface @ 150% luminosity, with an upper vale gray color.
Shadows turned off, the only light in the scene set to 0, as well as the ambient light set to zero.

I think this is the beginning of a whole new aspect of LW rendering for me - I have tried countless times to get these types of shadows, using area lights, because I figured that's how it was done.
Granted, this scene is nothing special, but I'm excited now, and planning on trying multiple surfaces on the "background" sphere.
Thanks again! :)

IMI
05-13-2007, 03:23 PM
Surprised nobody is suggesting a occlusion shader. Its way faster then a sky-dome or BG radiosity. 9.2 has Occlusion || that lets you use a images as light probes.

///


I was reading about that recently, gonna try some of that out too, although I have to admit I'm not well-learned on the light probe/hdri thing... all in good time. :)

hrgiger
05-13-2007, 03:32 PM
How fast would a occlusion shader be? I just ask because the Fprime renders took about a minute.

I should have mentioned IMI that Fprime will render the objects faster if the skydome is in a seperate layer then the actual objects. Not sure of the reason, I just know this has been my experience.

IMI
05-13-2007, 04:12 PM
Oh well I wouldn't have noticed the difference, I guess, because I almost always have separate objects in separate layers, but I do appreciate it. :)

Edit:
Yeah, you ain't kidding about FPrime rendering this exceedingly quickly - the image I posted was 234 or so passes, in about 5 minutes. I started an F9 render in Layout, and after about 30 seconds it was obvious it was going to far exceed that.

hrgiger
05-13-2007, 06:34 PM
Don't count LW out as a possible render solution for this type of scene. I haven't kept up on all the rendering improvements that went on in 9.2, but I'm confident you could get a very nice render in well under five minutes using LW radiosity. However, you really have to understand which mode to use and what settings are good. There are many people on this board that would be better at telling you what a good setting might be.

But for simplicity sake and ease of setup, it's a snap with Fprime 3.

Also, be aware that using different surfaces on a luminous skydome is likely to produce more noise and will take longer in Fprime to clear up. You can see that in the second render in my example previously. I usually prefer to use the third option which is a low luminescent dome used in conjunctions with LW light types. And again, the only reason I use a skydome over just changing the background color to white or whatever, I just like using numeric values with luminosity instead of colors with background.

IMI
05-13-2007, 07:22 PM
No, I know. Every time I talk about FPrime, I worry that I'll sound like I'm slagging LightWave's render engine, but that's not the case at all.
Things like my little experiment above are better-suited for FPrime, because, for one, it's just a test, and for another, it has nothing fancy in it.
When I'm working in Layout I almost always have FPrime running as I make changes to everything, so I tend to keep an eye on it, so it's easy to view it as the final word in the matter.
Frequently though, I'll save a nice FPrime render, then shut it down and do an F9 render, then compare the results. In most cases, FPrime is quicker, but in alot of cases, LW/F9 is better.
I also am a big fan of spotlights and shadow maps - FPrime can't do shadow maps, so it seems...

That having been said, aside from being a great render plugin, FPrime is everything LW's GLSL should have been. ;)

prospector
05-13-2007, 09:12 PM
FPrime is everything LW's GLSL should have been.
Quit slagging LW :D