Fractal/Glitch Effect on only visible part of layer
I've followed Javert's video on using fractal effect to create a glitch effect, and it's doing what I want...to an extent :)
I've got a chroma-keyed composite shot of myself in front of a green screen and I want just myself to glitch, not the entire layer - is that possible? I've added a coloured background to the layer to show what I mean - I only want the effect on the blue me bit.
If anyone has any suggestions on that or how to produce some sort of interference/glitch, I'd be very grateful.
Thanks in advance.