New shader that I’ve started for making a ‘Dirty Lens’ effect,
https://www.interactiveshaderformat.com/sketches/3213
It is mostly based on the IQ shader for ‘value noise’ with a few small tweaks to make some parameters adjustable, and then used to mask a video stream.
The two basic techniques that I added were settings for optionally modifying the level of noise based on the distance from the center and applying a ‘power curve’ to the noise to push it more towards darkness.
It includes 3 different alpha modes, one where it keeps the alpha and just makes pixels black, and two settings (multiply and replace) for adjusting incoming alpha so that the black portions show through to other layers for composition.
