Color curves

Hi creators
Of course, Photoshop Curves is a very powerful color grading tool. How do I do something similar using shaders?
How do I change input value to different output value of a color channel ??

Inigo Quilez has a great chapter on this in the book of shaders. It’s about “shaping functions” that can be used to generate or modify textures.

A super basic version of this in spark, is simply using the smooth step patch on a texture. It acts as an s-curve, just like in photoshop.

I ported the curve plotter from the book of shaders so you can use it directly in Spark. It’s a great way to visualize color adjustments.

Curve Plotter.arp (5.0 KB)


Related, here’s another patch that can be used to test color adjustments.

POP_ColorTester.arp (7.2 KB)