View Full Version : some old pics on building light domes

09 September 2002, 04:25 AM
hey everyone, i dug these pics up off my comp, i was gonna use them to show how to create a light dome by hand, but i thought it was useless, but maybe some one will get something out of these pics.

8 lights
25 lights
52 lights
69 lights

09 September 2002, 09:39 AM
Blur your shadows, it will look much better (with less lights).

The 69 Lights setup is clearly GI, and not a skydome setup (unless the extra 17 lights introduced all the noise :) ).

09 September 2002, 12:27 AM
my softwere doesnt even have any gi :sad: , the 69 lights is sky dome, all of the shodaws intertwine to make the noise. i did it up to 180 lights, but my computer isnt fast enough to render anything above that

09 September 2002, 02:23 AM
hey .:Jupiter_Jazz, i think EVERYONE sees that the last pic is GI.;) just look at it for yourself. see the huge difference to the 52 lights pic! these 17 lights will never make such a difference. there suddenly is noise and the shadows are blurred. try to explain it or send someone a file containing the scene with the 69 ights and let him render it. if he gets the same result i'll apologize. i swear! :D;

09 September 2002, 05:58 PM
ok, does any one here have animation master? i would be happy to send them the scean. if no one has it i can post screan shots so you can count the lights yourself, but that wouldnt really be any proof.

09 September 2002, 05:35 AM
hey, i guess it means i did a good job tho, so i'll lake all this as a complement. i guess this proves that you dont need to rely on softwhear to do gi, you can do it yourself :p so now people should stop complaining about there programs not having GI. animation master(thats what i use) has a crappy renderer, but if you make your own gi, and use good textures it doesnt matter.

09 September 2002, 09:54 AM
Please explain why the picture with 52 light looks crappy and the one with only 19 lights more looks like GI all of a sudden.

Look at the distance between the shadows in the 52 lights image, you are saying that with 17 lights more that distance is reduced to a smooth gradient?

Like derwolpertinger said, 17 like more will nog give you that effect. I know because I use these setups all the time (with about 100 lights).
Also, fake skylight setups never introduce noise like in your 69 light image. The shadows are always clean (thank god, because else you couldn't use it for animation).

It really is a nice effect, but it is not always a replacement for true GI. It works great in closeups, but when you have to do huge terrains spanning large areas you will come into trouble with your shadow maps being too small (or taking up too much memory).

09 September 2002, 09:39 PM
here are some screen shots, it probobly wont prove anything, but you never know.

09 September 2002, 09:41 PM

09 September 2002, 02:51 PM
...And btw, I've tried it myself on AM. And it DOES look like GI above some limit of lights.
And it doesn't have a built-in GI renderer. :)

09 September 2002, 04:16 PM
Any render engine will make this grain effect above a certain number of lights. There are only so many samples that are taken by any render engine...

09 September 2002, 04:50 PM
That is a very weird effect, I have never had such problems in 3d Studio Max. I can add as much lights as I want and I never get noisy renders.
My apologies for my disbelief, I am convinced now :)

Does Animation Master have the option to blur the shadows (blurred shadow maps?), that way you could achieve a good effect with only 50 or so lights (thus avoiding the noise problem).

Any render engine will make this grain effect above a certain number of lights. There are only so many samples that are taken by any render engine...

Not all render engines take random samples like Brazil of Final Render. I've did a little test in Max with the same setup but with lots more lights (768 to be exact) and there wasn't any noise whatsoever..(luckily, because else this technique would be useless for animation).

09 September 2002, 08:11 PM
and so here is my apology jupiter jazz!;) didn't knew about high samples creatin noise shadows. gotta try it with my software.

09 September 2002, 12:25 AM
hey thanks guys.
marcel: there is 2 ways i could blur the shadows, i could use z-bufferd shadows, but those are only available for spotlights, or i could make the lights have more ray casts, and that would bump up the render. say if i put it at 2 raycasts, that would double the render time. so for now im happy with the grain :), until i get a faster computer

09 September 2002, 09:46 AM
hey thanks guys.
marcel: there is 2 ways i could blur the shadows, i could use z-bufferd shadows, but those are only available for spotlights,

Definatly use Z buffered spotlights (which are called shadow mapped lights in some applications).
Z buffered lights are much much faster than Raytraced lights, and the ability to blur the shadows is great.

I can imagine that 69 raytraced shadow lights make you computer run slow, but the idea of using that much raytraced lights is just a little bit insane :) (I'd already be afraid using 3 raytraced lights, let alone 69!)

09 September 2002, 09:10 AM
I use that same kind of setup for faking GI in Animation Master all the time, so I'm pretty sure he is not using real GI.
I would usually use a skydome of around 20-30 lights casting maybe 3 rays each, to reduce the grainyness. Sure it can get a little slow but produces pretty good results.
Here's an example of how I would use the technique:

Animation Master does have built in radiosity and global illumination (at least in the version I'm using - v8.5), though with poor control and render speed.


09 September 2002, 05:44 PM
in version 9.5 they take out the global illumination, and put in global ambience, and all that does is put a solid white shade over everything, and it makes everything look flat. and the radiosity right now is almost impossible to work with. but such is life ;) its good to see another hasher around here

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