Topic: SmoothFollowWithCameraBumper

This is an updated version of the script SmoothFollow2.  I updated the script with a design to prevent the camera from passing through objects while following the target. A ray is cast out the rear of the target and if it collides, the camera will adjust to prevent passage into the object.  I originally updated this script in Unity JavaScript but someone has also ported it to C# on the Unity wiki.

Place this script onto a camera and select camera target in Inspector. Tweak bumper settings to achieve desired affect.

Code is below and you may also get it from the Unity wiki website.

var distance : float = 3.0;
var height : float = 1.0;
var damping : float = 5.0;
var smoothRotation : boolean = true;
var rotationDamping : float = 10.0;
 
var targetLookAtOffset : Vector3;         // allows offsetting of camera lookAt, very useful for low bumper heights
 
var bumperDistanceCheck : float = 2.5;    // length of bumper ray
var bumperCameraHeight : float = 1.0;     // adjust camera height while bumping
var bumperRayOffset : Vector3;             // allows offset of the bumper ray from target origin
 
// If the target moves, the camera should child the target to allow for smoother movement. DR
function Awake()
{
    camera.transform.parent = target;
}
 
function FixedUpdate() {
 
    var wantedPosition = target.TransformPoint(0, height, -distance);
 
    // check to see if there is anything behind the target
    var hit : RaycastHit;
    var back = target.transform.TransformDirection(-1 * Vector3.forward);    
 
    // cast the bumper ray out from rear and check to see if there is anything behind
    if (Physics.Raycast(target.TransformPoint(bumperRayOffset), back, hit, bumperDistanceCheck) 
              && hit.transform != target) { // ignore ray-casts that hit the user. DR
        // clamp wanted position to hit position
        wantedPosition.x = hit.point.x;
        wantedPosition.z = hit.point.z;
        wantedPosition.y = Mathf.Lerp(hit.point.y + bumperCameraHeight, wantedPosition.y, Time.deltaTime * damping);
    } 
 
    transform.position = Vector3.Lerp(transform.position, wantedPosition, Time.deltaTime * damping);
 
    var lookPosition : Vector3 = target.TransformPoint(targetLookAtOffset);
 
    if (smoothRotation) {
        var wantedRotation : Quaternion = Quaternion.LookRotation(lookPosition - transform.position, target.up);
        transform.rotation = Quaternion.Slerp(transform.rotation, wantedRotation, Time.deltaTime * rotationDamping);
    } else {
        transform.rotation = Quaternion.LookRotation(lookPosition - transform.position, target.up);
    }
}