CGTalk - Color-Pick channel to scaler value

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Tanya613

09-09-2007, 09:17 PM

I am making an expression to drive the y transform of on object with the average color of an image.
I have a gray image that ranges from .624 - .645 +\-
Render tree: Image lookup --> pick channel (red) --> scaler2color.....

I am drag&dropping the input node of the scaler2color to the expression editor, it validates, but always gives a value of .5

Any help would be appreciated.

Tanya

tachy0n

09-09-2007, 11:05 PM

Rendertree nodes are mentalray shaders. They don't evaluate outside a render and AFAIK you cant use their output to control scene objects.

To control an object based on an image, you can create a SCOP and use GetPixel()/GetPixelArray() Try the SDK manual for details.

Tanya613

09-09-2007, 11:58 PM

Thanks tachyOn,

Thats exactly what I needed, I've worked all weekend trying to get it with vector states, savestates, etc. But this is what I wanted.....no pain no gain!

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09-09-2007, 11:58 PM

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