View Full Version : Incandescence in shadow only?

07 July 2010, 03:50 PM

I'm rendering the earth. basically using a map for the lights in the incandescence channel of my shader. however, I need it to display in the shadow areas only with a zero gradient to fully lit areas.

anyone know how to achieve this?


07 July 2010, 03:52 PM
Surface Luminance node is your friend. Use this to control the color gain of your texture map.

07 July 2010, 04:21 PM
you know I've been starring at that node just now wondering what to do with it ;) thanks MasonDoran.

07 July 2010, 04:33 PM
by the way, dont suppose you know what outputs/inputs to connect?

07 July 2010, 04:58 PM
I've plugged the surface luminance out value into the colour gain R,G,B of the incandescence, though it seems to be doing the opposite, the incadescence only shows in the lit areas :(

07 July 2010, 06:47 PM
BUMP!! still cant get this working :( wasted a good few hours with the Surface Luminance node so guess that doesn't work.

any suggestions anyone???

07 July 2010, 06:52 PM
it is the correct node, just requires some research

07 July 2010, 06:58 PM
you're right MD, got it working now :rolleyes: Just requires pluging the SL into a reverse node :cool:

07 July 2010, 07:09 PM
just to verify....i just got working by following the link i just provided

07 July 2010, 07:11 PM
The reverse node isn't neccessary.
You can get two for one functionality by connecting the surface luminance outValue to the vCoord of a ramp (assuming the default V-type ramp).
You can get very fine control of just how you want you values to fall off and what colors they are.

***big note is that you do need to use the setValue node or the clamp node in the chain to keep your ramp from repeating as the luminance may go over 1***

Love this node!

07 July 2010, 11:46 AM
MasonDoran: cheers, that link also has alot of other useful tips I can use ;)

animatedfox: Thanks for futhering this. Adjusting the values would be an ideal function as too much of the map is still visible in the light. Will look into this method also.

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07 July 2010, 11:46 AM
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