GM_ROUND_MATTE
This is a simple tool I made when I had to quickly create a certain UI design in Nuke.
It is certainly could have been made easier in some vector graphics software but as it was just part of the challenge opening another application seemed too much effort to spend on the task at hand.
The only thing I needed is a setup that curves the corners on the alpha channel as this design happens almost everywhere in contemporary UI design. The setup in its core two key_cew nodes where the second has the reversed value of the first one.
Once I had the setup it was just a small step turning it into a gizmo.
ROUNDNESS/
Allows you to round down corner on the alpha channel.
EDGE CONTRAST/
Allows you to adjust the contrast on the alpha`s edges.
KEEP CONCAVE ANGLES/
Allows you to enable/disable concave angles on the alpha channel.
PREMULT/
Allows you to premult the alpha with the rgb channel.
MIX/
Allows you to adjust the mix of the original and the modified alpha.
Here`s a quick setup of the type of thing you can do
quickly with this node: