I'm trying to make my own first-person character (because I get lost in the sea that is Unity's FP character script), and am trying to make it so it detects when it is standing on a floor. I tried using a playerController, but I've found rigidbody is just more malleable.
Anyways, so I think how you'd do it is finding the direction of the contact, and if it isn't straight down, then to keep onGround as false. I'm just not entirely sure the scripting behind this, and several searches have turned up nothing.
Several offered using mutliple colliders, but I would prefer to keep the number of objects, colliders or otherwise, at a minimum, considering there will be a large number of them in the scene as is. I also want something that's easily manipulable so that I can add extra features like climbing up a wall or the like, and I think that measuring the angle to the center is about as simple and easily manipulated as it gets.