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DenisaM
07-11-2009, 09:38 AM
Hello, i'd like to ask for some experiences about liquid and glass lighting / environment reflection for animations.
I'd like to make something like this: http://www.alien.sk/files/9/CCprodukty.jpg

I'd like to use 3dsmax + vray renderer

thanks for help :)

mister3d
07-11-2009, 09:46 AM
It's pretty obvious: 2 area lights from sides to get reflection from sides, perhaps they have a gradient to look more realistic. And the background is a seamless sweep lit with a spotlight or something.
Glass is almost never lit from the front, all you care is about the edges and background lighting. There is a physical exaplanation why you light it from sides, but I don't remember it.
One more important thing is that you can control the size of the black edge in glass by increasing the size of the seamless sweep: if it goes just by the frame edges, you will get the biggest edges in glass, and if you increase the sweep, the edge becomes more subtle.

DenisaM
07-11-2009, 09:55 AM
It's pretty obvious: 2 area lights from sides to get reflection from sides, perhaps they have a gradient to look more realistic. And the background is a seamless sweep lit with a spotlight or something.
Glass is almost neve lit from the front, all you care is about the edges and enough background lighting.

Thanks for fast reply. I'm trying this gradiants a few days but it doesnt looks so mutch great.
Here's some of the renders:
http://www.cgsociety.cz/beer214154.jpg
http://www.cgsociety.cz/pivo_web.jpg

mister3d
07-11-2009, 10:10 AM
Thanks for fast reply. I'm trying this gradiants a few days but it doesnt looks so mutch great.
Here's some of the renders:
http://www.cgsociety.cz/beer214154.jpg
http://www.cgsociety.cz/pivo_web.jpg

Well, there are some points I see:
-in your coca-cola reference, pay attention that sidelights are not equal, i.e. not symmetrical. Symmetry in lighting is what you should avoid as it's way too static, especially with centered objects like products, which are already pretty fixed. So make one light not equal either in position or intensity
-you seem not having a good black edge, thee's something with your shader. Set "exit color" to black perhaps, and check if your liquid is done correctly: it should overlap with the glass a bit in vray. And once again, watch the sweep going just behind the edges of the frame, not much more
-the arealights in your renderings are way too subtle, make them much brighter: look in your coca-cola examples, they are almost white, this gives a nice sense of contrast
-in both your renderings, the background should be more subtle to me: first of all the line below is too contrasty, and attracts too much attention. That's why you use a sweep - to get rid of distracting edges. In your coca-cola example all you pay attention to is bottles, and it should be like this. In the darker variant, maybe try to make the background gradation a bit more subtle
-the framing could use more space around the glass, just my opinion.

israelyang
07-16-2009, 07:51 PM
maybe this will help.
http://www.lowel.com/edu/lesson_lighting_glass.html

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