Need Help: Lighting a building without radiosity...

[EricMLevy]

Try making an array of omni lights, without shadows on:

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maybe do like 4 x 4 x 4, all spread apart,

and then set up a simple 3 point lighting, all with shadows.

There are a million links to lessons of 3 point lighting...go find one. Oh, and turn on Inverse or Inverse Square decay on all the lights.

So, mess with these values, and also try an omni array with more lights.

If you turn shadows on the onmis it will look much more realistic, but with pump the render time way up.

Screw GI,
Eric

[brap]

You could also try Overcaster (part of Eki's Plug Pak). It sets up spinning light rigs automatically. Don't know however if it works with 8.
http://www.kolumbus.fi/erkki.halkka/plugpak/index.html

[MooseDog]

if you have some patience, or a bit of time, try messing about with the gMil shader. this simulates bg radiosity on a per-surface basis, w/o invokining radiosity per se. google gMil, and the book 1001 t.n.t has a good description as well.

[Muad'dib]

I second the notion of checking out overcaster & gmill - as well as that you can also check out lightgen ( I think that's what it's called ) - basically it lets you set up lights from images and works like a treat. Sorry don't have an image as an example here atm.

Also .. and I'm only saying this from experience ( I worked on a 20x10 meter piece here in Melbourne ) ... I assume you have but just in case you haven't - contact the people that will be actually printing this and find out how low you can go in terms of resolution 'cause sometimes ( because of the process / final materials/stock ) they don't need as much as you'd think.

[gerardo]

Bake the illumination on textures.


Gerardo

[Guillermo]

Thanks a lot for the tips guys! :) I´ll try those plug-ins seem very useful. I´ve got FPrime and works really well and fast too.


Thanks again! :)

[Kvaalen]

You can use the spinning lights trick (what Overcaster does for you) but that won't work with FPrime (because of the motion blur).

I'd advise you to bake the shadows the way gerardo said, then FPrime will handle it easily and the render will be extremly fast!

[blacknoise]

"spinning lights" would do fine i think...
now it all looks a little bit flat. especially the road.
keep working.

[EricMLevy]

the omni array is simple, very configurable, and easy to use...screw the plugins.

regardless of what you choose though, you should also be 3 point lighting your scene on top of the fake GI.

-E

[Protean]

Bake the GI as Gerardo said.. I've just done a complicated architectural piece at work using baking and it worked real good.

[uncon]

I have to throw in my vote for baking, it will take a while but when it's done you can even render off nifty animations. Just make sure you just bake out the illumination and don't make it so High a resolution otherwise it will take forever. The baking shouldn't include shadows, Just bake in the ambient light and use your key (I think it's called the key) light to put shadows on there.

[webfox]

I don't have anything to add concerning lighting, but from a printing standpoint, I don't believe you need to render an image 11,000 pixels across.

Your image is only about 70 DPI and will be somewhat blurry to begin with at that size. If you rendered at half size, and blew it up on PS, it should look the same.

If there are reasons for such a large render, then I won't argue, but this has been my experience doing renderings for trade show booths.

Good luck in your project.

[policarpo]

try using splitrender for this large render.

cheers.

http://www.frenchwave.org/SplitRender/#US

[gerardo]

If you have FPrime, you can use it to render the occlusion pass much more quickly (for Multipass render). If you want to go for spinning lights, you can use Overcaster and to replace the spot lights for area lights, since FPrime calculates them more quickly, you can even use area lights with quality 2 for the lights that cast shadows and 3 for negative lights. However to make it with the native LW render and spotlights, is quicker yet; but is more difficult of adjusting to achieve good results.
Although I continue thinking (if your you don't want to make multipass rendering) to bake the illumination in textures, at least the ambient occlusion map, can be quicker in this case, and to use the key light as Uncon says.



Gerardo

[Guillermo]

Thanks a lot for the responses guys! :) The baking solutions could be fine... anyway I´ll ask the printers which resolution are they gonna need. I thought on rendering at half resolution and make it big in photoshop.

Thanks a lot!

[Jaspar]

I would also like to thank you all, because I've been having the exact same challenge. I personally would have used baking, but I have a few objects that would be a total nightmare to create a UV map for.

I would like to extend the question a bit further. I've been using an array of lights to light my scene, my problem is with balancing the indoors and outdoors. To get a good look for the outside (and to avoid overblowing the indoors), I've given all the lights ray-traced shadows. The problem is, those shadows don't look so good inside the building (Ideally I just want one or two key-lights creating shadows indoors). Would you all say it's best to use falloff, or should I just be using two scenes, one with an indoor lighting rig, one with an outdoor one? My best solution so far was to use a lighter colour for the shadows, and to use weak clones without shadows.

Are there any good methods (or plugins) to make quick non-overlapping UV's purely for the purposes of baking?

I'll post pictures if anyone is interested.

Thanks.

[maximus]

before that i had problem to render an A3 size in LW 8.....until now i still had no idea how to solve it.
"memory problem..." thats what the applications shows..

my machine had 2GB ram

see if u got any sulotions

thanks

[MK2]

For the light problem... alternative: you can try to bake the vertex colors... remove the textures and render it black and white then you can blend textures and Vertex colors... but you need a lot of polys to have a good vertex light. Or you can try to paint the the vertexes by Hand.


For big size renders you can try a tool called PhotoZoom Pro (S-Spline) its a tool for resize pictures. We used it to resize some PS-1 screenshots for advertisments.

[gerardo]

I would also like to thank you all, because I've been having the exact same challenge. I personally would have used baking, but I have a few objects that would be a total nightmare to create a UV map for.

I would like to extend the question a bit further. I've been using an array of lights to light my scene, my problem is with balancing the indoors and outdoors. To get a good look for the outside (and to avoid overblowing the indoors), I've given all the lights ray-traced shadows. The problem is, those shadows don't look so good inside the building (Ideally I just want one or two key-lights creating shadows indoors). Would you all say it's best to use falloff, or should I just be using two scenes, one with an indoor lighting rig, one with an outdoor one? My best solution so far was to use a lighter colour for the shadows, and to use weak clones without shadows.

Are there any good methods (or plugins) to make quick non-overlapping UV's purely for the purposes of baking?

I'll post pictures if anyone is interested.

Thanks.



I don't understand well why you have problems to create UV maps to some objects in your scene. The UV maps you need is to bake illumination in textures, not to paint on them, for what you can use Atlas proyection since you don't need the UV map has a specific shape.
If you refer to some indoors objects and you don't want to bake textures, you can use spinning lights just for problematic objects.
Regarding the outdoors and indoors illumination, (is difficult to give an opinion without seeing your images) you can use soft shadows (spot lights or area lights) for most of the lights and only use sharp shadows for the keylight. If this doesn't work, I think is better to set up outdoors and indoors independently.
The other way of achieving it without baking illumination in textures is to make everything with spinning lights; is relatively simple for outdoors, but for interiors is another history, however Innercaster is a good starting point:

http://www.cgtalk.com/showthread.php?t=144132&page=1

but in general the spinning lights is not easy to use for interiors, reason why if you aren´t still familiarized very well with its operation principle, bake illumination in textures can be quicker, in spite of UVs. :)
I don't know if this helps in your case, but I find interesting the Yog answer in this thread about UVs:

http://www.cgtalk.com/showthread.php?t=150555




Gerardo

[Jaspar]

Thanks for the reply Gerardo. I don't know why I hadn't considered using atlas unwrap, it makes perfect sense that it'd be the way to go if I were to try and bake. Think I'll need a lot of patience to set up maps for every surface in the building, and wait for the baking, but I'm sure it'd be worth it.

I've never been quite happy with the spinning light trick. I have tried using it via eki's plugpak, but always seem to return to classic three-point rigs or radiosity. Referring to the thread you posted, those innercaster images look amazing, so I'll definitely try it out with F-Prime. I had thought that innercaster had used the spinning light trick, and had got the impression that it didn't work with f-prime.

In my case area lights would just be too slow, I'm planning to render out animations for an interactive web site on an intranet. I had got results that I was reasonably happy with with radiosity, just couldn't bear the thought of waiting a few years to render out the thousands of frames I would require! Have decided that your definitely right that baking is the way to go.

Am attaching a ray-traced shadow render, just for your interest. I had set up an array of 16 lights in a sort of sky dome effect, and had cloned 8 of them to soften the shadows. Unfortunately, I was still ending up with those rather busy selection of shadows. I had been dreading the idea of setting up maps due to the shear number I'll have to create, this model's a long way off finished. It's a model of my workplace, it houses around 500 people, has three wings, three floors in each wing, and i'm planning to include details such as power points, signs and fire hydrants. Just to test my sanity, there are no useable blueprints, so I have to measure everything by hand. Oh, and I'm not getting paid for this, I'm just doing it for fun! Please excuse the outburst, just couldn't resist sharing my pain!:scream:

http://website.lineone.net/~jaspar.cadenhead/PostPics/Arena110704.jpg

(Thanks Again!)

[gerardo]

Jaspar, I can´t see the image you attached; can you post it again? (seems an interesting and very difficult project)
Btw, I don't have problems here with spinning lights and FPrime; and to thread you refer, I didn't use FPrime; everything is spot lights and LW native render (they are quicker than FPrime with area lights) :) however if you plan to do an animation of such an extensive project, definitively I go to bake illumination in textures.
Another way to make it is with Multipass Renders, (for color layers, occlusion, shadows, reflections, etc) and compose everything in post. In this case, FPrime is your best option.


Gerardo


Edit: mmm...weird, I can see the image now. Looks really good! :thumbsup:
Maybe you can replace distant lights for spot lights in your skydome and spin it.

[Jaspar]

Thanks once again. I had tried the spinning light technique with this rig before in F-Prime, not on the normal small scale, but by spinning a parent null in the centre of the building. Needless to say, it didn't work, the shadows were moving all over the place from frame to frame. I would try it on the individual null, small movement set-up, but it would take a while to set up, and I reckon I'll end up with a flicker. What revs per frame should I be using? I had a feeling it was 720 (to account for the 50% blur)?

Am looking for any excuse to start using DFX more, but think I'm going to skip the multipass for now. Seems like a good thing to use if I add a character later.

Once I've baked, would I generally use Ambient light to light the scen, or would I give the surfaces 100% luminosity?

Cheers.:thumbsup:

[gerardo]

To determine the rotation angle of the Null that spins (we´ll call it L_Spin), you should count how many lights (or light columns) you have to illuminate. Theoretically with motion blur of 50% and a single light (or a single light column), L_Spin should rotate 720 degrees; but in fact, this isn´t this way, since if rotates 720 degrees, the last passing will repeat in the first one and we´ll have a darker area there; we are also wasting a passing that could eliminate the bands effect. To know which the angle should be, you can apply this formula (of Dug Stanat):

720 * (#OF AA SAMPLES - 1) / (#OF AA SAMPLES).

720 considering the motion blur is at 50% and 360 if is to 100%.

Example:

For Enhanced Medium Antialiasing (Motion Blur Dithered) we have 9 passes (Medium) but as Motion Blur is Dithered we count 18 passes, then the formula would be this way:

720 x (18-1)/18 = 720 x (17/18) = 720 x 0.9444444444444 = 680

Then for a single light (or lights column) we should rotate L_Spin 680 degrees and not 720 as commonly is thought.

if we say, you have 12 columns of lights (or 12 lights around the objects) you should divide 720 / 12 = 60, then in the formula we use 60 instead 720.

Another important aspect so that your illumination doesn't vary from frame to frame, is the keyframes should be exactly in frames 0 and 1 respectively (PRE and POST Behavior REPEAT).

For the Bake, depends; I recommend you use the same lights (with all shadows disabled except for the keylight) and only make an occlusion map that you can put in Difuse Channel later.



Gerardo

[Jaspar]

Wow, thanks for the comprehensive reply! I'll find that really useful.:thumbsup:

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