Forcing a Character Controller to slide down?

[Seith]

Hello, I’m using a Character Controller on my third-person character, which works pretty well, except in one case: When the character steps just beyond the edge of a cliff but the base of the capsule-shaped character controller still touches the edge of the cliff.

The result is the character magically floats in the air instead of falling. Is there a way of “forcing the character down” so that it’ll slide and fall even if a tiny part of its controller’s base is in contact with something?

[Nervous_Nerve]

Bumping, since I’m having the same issue.

I’m thinking it happens because CharacterController is using the CollisionFlags returned by the Move function to determine if it ‘isGrounded’. Since the edge is touching the bottom part of the capsule, CollisionFlags.Below is true and therefore we are grounded.

Anyone been able to solve this?

[Polinator]

The messy and dirty way I did something similar to this is that I made triggers of when they are at the edge. You can then AddForce, or MoveForward, or SetVelocity forward just a little bit, so that then the character controller does go off the cliff.

Again, it’s dirty but that’s what I’ve used. If there’s any other options I’d like to know as well.

[Marsupilami]

If your character controller parent game object has children with colliders (primitive or mesh) they will cause problems with the character controller’s ability to handle collision. Try removing colliders from any children.

I spent an hour messing with slope, skin and step offset until I tried removing the collider from my head mesh then adjusting my body collider to also cover the head. Cleared my issue right up and I was able to put my slope, skin and step offsets back to realistic values without any issues. Makes calculating headshots a little more tricky, but I’ll probably just replace the character controller with a custom one eventually.

[sadjigfdsigfwk]

Add the following to your code:
// Making sure that when the player is not colliding with any object, he is suspended in air must handle aerial movement

bool m_IsColliding;

       void OnCollisionStay () {
		m_IsColliding = true;
	}

	void OnCollisionExit () {
		m_IsColliding = false;
	}

// Inside the Move function replace:
			if (m_IsGrounded)
			{
				HandleGroundedMovement(crouch, jump);
			}
			else
			{
				HandleAirborneMovement();
			}

// with:
if (m_IsGrounded) {
			HandleGroundedMovement (crouch, jump);
		} 
		else if (m_Animator.GetCurrentAnimatorStateInfo (0).IsName ("Grounded") && !m_IsGrounded && m_Animator.GetBool("OnGround") && m_IsColliding) {
			m_IsGrounded = true;
		}
		else
		{
			HandleAirborneMovement();
		}

// replace HandleGroundedMovement function with:
void HandleGroundedMovement(bool crouch, bool jump)
	{
		// check whether conditions are right to allow a jump:
		if (jump && !crouch && m_Animator.GetBool("OnGround") )
		{
			// jump!
			m_Rigidbody.velocity = new Vector3(m_Rigidbody.velocity.x, m_JumpPower, m_Rigidbody.velocity.z);
			m_IsGrounded = false;
			m_Animator.SetBool("OnGround", m_IsGrounded);
			m_Animator.applyRootMotion = false;
			m_GroundCheckDistance = 0.1f;
		}
	}

[ndruha]

It’s simple to fix with CharacterController:

// Somewhere in your update
if (_controller.isGrounded && IsOnTheEdge()) {
    _controller.Move(transform.forward * 2f * Time.deltaTime);
}
...
        // Function to check if the character is on the edge
        private bool IsOnTheEdge() {
            if (Physics.Raycast(transform.position, Vector3.down, out var hit)) {
                return !hit.collider.isTrigger && Vector3.Distance(hit.point, transform.position) > 0.2f;
            }
            return true;
        }