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View Full Version : proper Rim light / back light

cheerfulskeptic
03-07-2008, 07:08 PM
Hi everyone,
I'm using 3DS max 9, and I've recently gotten into lighting with Mental Ray. My lighting comes out fine, except the rim light... The fill, key and bounce lights light the scene up nicely, but the rim light is either too thick, or goes all over the place.. I'm placing a spotlight at around 80 degrees over the subject, and directly opposite to the camera and a bit to the left/right. I either get a thick or no rim light.. I've tried rendering the rim light as a separate pass on a blank blinn material, but still no luck. What am I doing wrong? I'll try posting a scene...
Thanks
SanjayChand
03-07-2008, 09:59 PM
Try a directional light with no shadows.
frizDog
03-07-2008, 11:09 PM
Material settings are also a big part of rim lighting. . .
do you have enough fresnel effect contributing to your shader?
cheerfulskeptic
03-08-2008, 07:20 AM
well, I'm using a standard default blinn material for the rim lighitng pass and compositing it on my final animation... was using a spotlight for the rim, but will try directional and will try the adjusting the fresnel values, thanks.
soulburn3d
03-08-2008, 03:36 PM
You could also try replacing all the materials in your scene with a black material that has a falloff set to fresnel in the diffuse slot (just for this render pass). Then when you render your rim light pass, the light will only strike some parts of the surfaces, and then those surfaces will only appear white on the very edge of the objects. Add those ontop of your other layers in the comp and you can get a pretty strong rimlight.

- Neil
cheerfulskeptic
03-10-2008, 09:12 PM
very nice, thanks Neil!

I'll try it out...
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