colors value to drive transforms

[rickvdvulkaan 1]

Hello everyone!

I'm playing around with the attributes adjust color node, which could open up some really neat workflows. I achieved some nice effects with for example the polyextrude on every individual element. Now i'm pretty sure this should be possible, but i was wondering if the color values could also trigger a transform on each primitive. So imagine the world "hello". The 'h' is black, and every letter gradually gets more white.

What is the most straightforward way to convert the color value to a scale value? so something like;  hello

[konstantin magnus 1,163]

f@pscale = luminance(v@Cd);