Rigidbody FPS Controller with slope climbing prevention

Unity Engine
1 
using UnityEngine;
using System.Collections;

[RequireComponent(typeof(Rigidbody),typeof(CapsuleCollider))]

public class fpscMovement_Phy : MonoBehaviour {
	
	public float walkSpeed = 2.0F;
	public float jumpHeight = 2.0F;
	public float gravity = 10.0F;
	public float slopeAngle = 0.85F;
	
	private bool onGround = false;
	private Vector3 velDesired = Vector3.zero;
	private Vector3 velCurrent = Vector3.zero;
	private Vector3 velDifference = Vector3.zero;
	private float velJump;
	private static float speed = 0.0F;
	
	private float collisionAngle = 0.0F;
	
	void Awake () {
		rigidbody.freezeRotation = true;
		rigidbody.useGravity = false;
		rigidbody.isKinematic = false;
		velJump = Mathf.Sqrt(2.0F * jumpHeight * gravity);
	}

	void FixedUpdate () {
		//Only move if on a solid ground
		if (onGround  collisionAngle > slopeAngle) {
			//Get desired velocity
			velDesired = new Vector3( Input.GetAxis("Horizontal"), 0.0F, Input.GetAxis("Vertical") );
				velDesired = transform.TransformDirection(velDesired);
			speed = walkSpeed * ( bool2Int( Input.GetKey(KeyCode.LeftShift) )+1 );
				velDesired *= speed;
			//Get current velocity
			velCurrent = rigidbody.velocity;
			//Get the difference in between
			velDifference = velDesired - velCurrent;
				velDifference.y = 0.0F;
			//Apply the difference to body 
			rigidbody.AddForce(velDifference, ForceMode.VelocityChange);
			//Get if want to jump
			if ( Input.GetButton("Jump") ) {
				//float velJump = Mathf.Sqrt(2.0F * jumpHeight * gravity);
				velCurrent = rigidbody.velocity;
				rigidbody.velocity = new Vector3(velCurrent.x, velJump, velCurrent.z);
				//onGround = false;
			}
		}
		else {
			rigidbody.AddForce( new Vector3(0.0F, -gravity * rigidbody.mass, 0.0F) );
		}
	}
	
	void OnCollisionStay (Collision collision) {
		//onGround = true;
		foreach (ContactPoint contact in collision.contacts) {
			if (contact.point.y < transform.position.y - 0.9F) {
				onGround = true;
				collisionAngle = Vector3.Dot(contact.normal, Vector3.up);
				//Debug.DrawRay(contact.point, contact.normal, Color.white);
			}
		}
	}
	
	void OnCollisionExit (Collision collision) {
		onGround = false;
	}
	
	void OnGUI() {
		GUI.Label (new Rect(0, 0, 100, 20), onGround.ToString());
		GUI.Label (new Rect(0, 20, 100, 20), collisionAngle.ToString());
		GUI.Label (new Rect(0, 40, 100, 20), slopeAngle.ToString());
	}
	
	private int bool2Int(bool b) { 
		return b ? 1 : 0;
	}
}

Above code is a physics based fps controller. Also prevents climbing slopes with a high angles.

Still it is better to use ray cast(s) to get the slope angle and collisions but this shall do because (im not sure) but oncollisionstay function does calculate before the fixed update so sometimes stucking around is possible.

2

thanks man you sent me on the right track

i made some changes too to make it stronger cos i dont use force

i changed

rigidbody.AddForce( new Vector3(0.0F, -gravity * rigidbody.mass, 0.0F) );

for

Vector3 gDown = new Vector3(0, 10, 0);

rigBody.MovePosition(rigBody.position - gDown * Time.deltaTime);

and it workes no crazy sending my man on a mission when he falls of a clif lol but get some jumping errors