View Full Version : Normalize surfaceLuminance input

 joie07 July 2009, 11:14 AMHi there guys; Is there a way to normalize the input of a surfaceLuminance node?. I want to use it with physicalSky and I need to divide the surfaceLuminance input by 300 or so to get a usable range... So I guess there must be a way to normalize the input instead of try and error to get the desirable range. Thank you in advance.
Ironhalo
07 July 2009, 03:02 PM
if you know a minimum and maximum range you could try a setRange node.

joie
07 July 2009, 07:51 PM
Yeah, I know that and is the method I'm using right know, to get the highest number I use the trial and error method.

But I'd like to know if there is more elegant solution..., just put a node or a chain of nodes to get the input normalize no matter the highest number.

el diablo
07 July 2009, 12:03 AM
condition node

joie
07 July 2009, 09:55 AM
Mmm, condition node?, how can I use that for my purposes?, I still don't have the highest number in order to compute something..., please enlight me :)

el diablo
07 July 2009, 03:58 PM
I use the conditionNode to clamp values but I guess that was not what you wanted. If you need the highest color value per channel use an arrayMapperNode per channel.

djx
07 July 2009, 01:35 AM
joie: I use a setRange and clamp (probably similar to what you are already doing). If I understand correctly you want a way to determin the maximum luminance for a given location in your scene at a given frame, and you will use that value to nomalize the luminance. Its kind of like a photographer would use a light meter to determin the exposure of his/her shot.

The only way I can think of is to render to float with no exposure node and then use something like aftereffects to see how bright a particular pixel is. And then figure out how that relates back to maya numbers.

-- David

joie
07 July 2009, 07:10 AM
Thank you, but that method is the same as my trial and error method ;)

I've found that the highest number with physical sky (with .318 power for real life accuracy) is actually somewhat near 320 (but not 318, that's quite funny isn't it?).

So I guess I can stick to that for now :)

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07 July 2009, 07:10 AM
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