Old charmove

using UnityEngine;
using System.Collections;

/// <summary>
/// Character motor for fps player.
/// </summary>
[AddComponentMenu("FPS Stuff/Player Movement")]
public class PlayerMovement : MonoBehaviour
{
    public float movementSpeed = 10;
    public float speedMultiplier = 1;
    public float maxVelocityChange = 10;
    public float jumpHeight = 2;
    public bool canJump = true;
    public bool grounded = false;

    void FixedUpdate()
    {
        if (grounded)
        {
            float h = Input.GetAxis("Horizontal") * movementSpeed * speedMultiplier * 0.7f;
            float v = Input.GetAxis("Vertical") * movementSpeed * speedMultiplier;
            Vector3 targetVelocity = transform.TransformDirection(new Vector3(h, 0, v));

            Vector3 velocityChange = (targetVelocity - rigidbody.velocity);
            velocityChange.x = Mathf.Clamp(velocityChange.x, -maxVelocityChange, maxVelocityChange);
            velocityChange.z = Mathf.Clamp(velocityChange.z, -maxVelocityChange, maxVelocityChange);
            velocityChange.y = 0;
            rigidbody.AddForce(velocityChange, ForceMode.VelocityChange);

            // Jump
            if (canJump && Input.GetButton("Jump"))
            {
                rigidbody.velocity = new Vector3(rigidbody.velocity.x, CalculateJumpVerticalSpeed(), rigidbody.velocity.z);
            }
        }

        grounded = false;
    }

    void OnCollisionStay()
    {
        grounded = true;
    }

    float CalculateJumpVerticalSpeed()
    {
        // From the jump height and gravity we deduce the upwards speed
        // for the character to reach at the apex.
        return Mathf.Sqrt(2 * jumpHeight * -Physics.gravity.y);
    }
}