Unity 镜头拉近效果(带缓冲)

var target : Transform;

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

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)) {

        // 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);

    }

}