Multiple physic surface in same material precedually?

Hello! I’m trying to make a Splatoon-ish effect. Currently, I made a material that I can paint with render target texture, but I’m not sure how to detect whether the player is currently on the paint or on the floor.


What I did is similar to the image above (credit to YouTube kai yan).

Is it possible to give the floor and paint different physic surfaces in the same material? Or are there other cost-efficient ways to do detect surfaces? Thank you!