CharacterController.IsGrounded

Hello.

I know there are plenty of threads that talk about the IsGrounded being "unreliable" but I think that someone must've found a solution to using it.

My code calls a Move method first so that the character can jump. Even though when you are grounded and the y velocity is 0, the Move method sets the IsGrounded to false for some reason.
Afterwards, I call the SimpleMove with a vector3 of zero to simulate gravity. This is the part I don't get. At some point, the IsGrounded gets set to true which is correct. But sometimes (even though I call the Move method with ZERO velocity) the SimpleMove method sets the IsGrounded to false. Why is that?

 

If I recall correctly, IsGrounded is set true if the bottom of the controller intersects an object during a Move. Pretty sure if CollisionFlags.Below is set to 1, then so too is IsGrounded. So if your object doesn't intersect anything at it's feet, it's not grounded.

What I do is just fire a SphereCast at the player's feet and use that to check if they're grounded. Gives me much more control over everything.

 

Does SphereCast work 100% of the time?

 

This is what I have in my Update method.

Debug.Log(characterController.isGrounded.ToString());
characterController.SimpleMove(Vector3.forward * 0); // Use world gravity

The CharacterController is above a flat plane and for some reason, even though it stops on the plane, it still sometimes logs False

 

I don't know what the hell I changed but the Move method is not setting the isGrounded to false anymore...

 

Oh I think it has something to do with me resetting the jumpDirection.y to 0...I'll try to figure it out. Thanks

 

So I have code where if the character is grounded, then reset the y velocity because otherwise then the y velocity will keep decreasing and when you fall you'll fall really fast. Apparently, if you set the y velocity too small (0 for example), I'm guessing the isGrounded flag is set to false. Then it'll see you're colliding and set it back to true but then my code resets the y velocity again and the cycle repeats.

 

So to kind of fix this, instead of setting it to 0, I've set it to a number low enough so that it doesn't jump into that cycle. In my case, -0.1 works and the fall speed is barely noticable.

 

Hi, I was having the same problem where setting a velocity.y of 0 would cause isGrounded to become false. By allowing a minimum move distance of 0 fixed it for me alternating between isGrounded true/false. Even the Unity docs recommend setting this value to 0, but then they default it to 0.001!