Lets Talk Lighting

[wizard]

well its pretty hard to explain lighting this way ,but the way that you can do like sunlight comin through the window and lighting things up for example is to work with direct lights for the sunlight .(with volumetric effect if needed) then try to put lots of omni lights inside the room like everywere up down around objects but it is very important that you use the "exclude,include," function on the objects and the shadows , play around with the light intensity..lets say you cast a direct light on the object cube but you can see it remains in total blackness from the other side ,the way i would do is to have an omni light with lets say 0.5 light intensity and put no shadows .this will effect the direct light shadow but you can go back to direct light and increase shadow map density and the shadow map type to 1200 ..just a small advise use shadow map size of min 1000 in complex scenes it's okay if it takes longer to render..well hope this helps alittle but the only way to do it is practice and lots of it ..good lighting comes from observation on real images or footage . :thumbsup:

[blc318]

Why dont you post up a pic of the room and your attempts? It would be easier to explain with an example of what you are trying to achieve.

[ilasolomon]

hi
well, i did some lighting test one or 2 years ago & this is
one of them (there are 4 of them, lighting this room, look @
my homepage)
if you are interested we can discuss about it here...
cheers

[blc318]

Please lets discuss. Ive been trying to do some lighting studys lately. This is one of my better attempts. The model is by Marko Dabrovic. and there are 8 lights in the scene.

[Taoizm]

Here's a really good place to start digging into light theory, and how to achieve good lighting with CG.

Jeremy Birn, he's been around, has a book out (which is excellent), and his site is chock full of goodies and links. Enjoy :)

http://3drender.com/light/index.html

[Lizard Head]

Lights.....to fake real light without a GI solution is a art on to its self,,,, I always start with the larger swashes of light and work my way down to the fine details.....

with a room I always start with the ambeint light setting first very very dark blue setting, then I set a non shadow casting, non-specular spot outside the room facing down for light that would be bounced from the ceiling,,and agin repeated from the floor up to mimic bounced light from the floor. then for the walls I place non specular omni lights just outside the room, one omni for each wall with decay ON and the range of the light cuts off just as it approaches the corners of the room to mimic the real life effect that right angles seem to produce with light. once I have a well diffused lit room I start to place omni lights with specular only on to bring out the highlights of things like glossy woods, hi gloss paints and such.

just some ideas

lizard*

[ilasolomon]

blc318, if u didn't tell there are 8 light i think it's GI or
atleast illuminated with 256 light! great job
could u explaine more about the lighting that scene?
wireframes + lights?
_ _ _ _ _

Lizard Head your technic sounds great, i didnt try seperate
diffuse/specular omines before, i will...
but i use direct spots for simulating bouncing light coz the omni
doesn't illuminate the objects same (cone light matter)

_ _ _ _ _

take a look @ these pictures, some of them are illuminated with
near 200 lights to simulate GI effect...all shadow mapped &
the rendering time was under 5 min...with a PC Celeron 333 + 256 mb ram

http://www.topleftpixel.com/ila/temp/©ila_103.jpg

i wll show the wireframe & lights situation.

[blc318]

uh Thanks. I still think it can improve dramatically. Ill upload the file and let you scope it out. The file was actually a little hard to work with b/c it was hard to exclude some geometry. Its basically one directional for the sun and the rest are just omnis where the sun hits the surfaces. All the bounce lights in this scene cast shadows and there is one or two fill lights. It would be hard for you to tell where the lights are placed with screen grabs so I hope this helps. Be sure to look at all the properties of the lights. Adjusting the contrast and diff edge values can dramatically effect your lights.


well the file is too big to upload here. So I will send it to your email:beer:

[ilasolomon]

thank you blc318
i tried to light this scene before but not much hard...& had no good
advantage on it with regular lights (no GI) yours is great

[Lizard Head]

BLC318!!! you know what,, been looking at that image of yours and I have an opinion,,, now before I give it , remember I hate making comments on others work,,, and your image there is top notch and done very very well!!!!! but, the one thing that I noticed is that it is an big space,, and there is no atmosphere in it,, as my eyes go further back into the architecture, i would think that the atmosphere would begin to take notice and start to appear,, and a hint of volume by the rays of sun would be a touch of effect that would really make that image of yours COOL

AWESOME work!!!!,, not trying to take away from you work here ,, just adding my opinion :)


lizard*

[blc318]

thats a great observation and I welcome your crit lizard head. I agree the volume and atmoshere need to be more prominent in the pic. Its there but I need to make it more dense. Please dont hold back anything. I will see If I can make it more dense and noticable.

[ilasolomon]

just some quick-study in simulating GI/radiosity with max default renderer:

[GlasS-]

If its not to much to ask for, could you please mail that last scene to me so i can study it? it would be very nice if you could, i suck at lighting scenes and would appreciate any help...

[Lizard Head]

GlasS-

That image of the cornel box that you want him to send you is available with MAX,, just boot MAX look in the tutorial section number 5 (intro to lighting) and you will see " faking bounced lighting" with the exact same set up and effects as you see in ila-solomons image...........great way to learn fake GI.




lizard*:drool:

[Sebastian]

If you want to understand lighting better, I advice you to get this book. http://images.amazon.com/images/P/1562059548.01._PE30_SCMZZZZZZZ_.jpg
It's called "Digital Lighting & Rendering" by Jeremy Birn.
It's a great read and everything is explained very well!!

Sebastian.

[GlasS-]

Thanks lizard!

[ilasolomon]

Lizard Head, only the mesh is the same, not lighting setup!
here is the light setup:

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