unity3d物体用鼠标拖拽旋转缩放展示

star-小虎

第一天学这个。。 var target : Transform;
var xSpeed = 250.0;
var ySpeed = 120.0;

var yMinLimit = -20;
var yMaxLimit = 80;

var initDis = 20;
var minDis = 3.0;
var maxDis = 50.0;

var wheelSpeed = 5;


static var x = 0.0;
static var y = 0.0;

static var distance;

private var position;
private var rotation;

function Start () {

x = 130;
y = 30;

transform.rotation = Quaternion.Euler(y, x, 0);;
transform.position = Quaternion.Euler(y, x, 0) * Vector3(0.0, 0.0, -initDis) +
target.position;

// Make the rigid body not change rotation
    if (rigidbody)
    rigidbody.freezeRotation = true;

}

function Update () {
     if (target) {
    distance = Vector3.Distance(target.position,transform.position);
    if(Input.GetMouseButton(1)){
     x += Input.GetAxis("Mouse X") * xSpeed * 0.02;
     y -= Input.GetAxis("Mouse Y") * ySpeed * 0.02;

     y = ClampAngle(y, yMinLimit, yMaxLimit);
    }   

    distance-= Input.GetAxis("Mouse ScrollWheel")*wheelSpeed;//获取鼠标中建响应
    distance = Mathf.Clamp(distance,minDis,maxDis);//距离取最大值和最小值

    rotation = Quaternion.Euler(y, x, 0);
    position = rotation * Vector3(0.0, 0.0, -distance) + target.position;

    transform.rotation = rotation;
    transform.position = position;

}
}

static function ClampAngle (angle : float, min : float, max : float) {
if (angle < -360)
    angle += 360;
if (angle > 360)
    angle -= 360;
return Mathf.Clamp (angle, min, max);
}

上面这个网上下的拖曳脚本

上面的脚本拖到cube里后还是不能用 会出现下面的错误

Assets/New Folder/NewBehaviourScript.js(49,23): BCE0051: Operator '-' cannot be used with a left hand side of type 'Object' and a right hand side of type 'float'.
怎么办