How can i create a switch with video in node

Im workin on a guitar effect switch. Im goingt to use this with a webcam. There wil be a white floor. when i want to put my foot on this area, sound will be changed. I’m going to add some sound effect nodes.(distortion/reverb)

How can i use webcam for a switch node? i hope you guys understood question. Sorry for my bad english.

Hope it helps.

blackbeard6612.v4p (15.4 kB)