In the following code along with my mouse cursor i can drag the components and place but i cannot zoom the components how can i do that ? i use to write this code inside a  normal camera

let grabbedActor = null;
let grabDistance = 0;
let grabOffset = null;
let rm = STU.RenderManager.getInstance();

beScript.execute = function (context) {
    if (grabbedActor != null) {
        let newPos = rm.getMousePositionIn3D(grabDistance);
        grabbedActor.setPosition(newPos.sub(grabOffset));
    }
};

beScript.grab = function (iActor) {
    grabbedActor = iActor;

    let actorPos = grabbedActor.getPosition();

    grabDistance = rm.getCurrentCamera().getPosition().sub(actorPos).norm();
    grabOffset = rm.getMousePositionIn3D(grabDistance).sub(actorPos);
};

beScript.ungrab = function () {
    grabbedActor = null;
};

beScript.onAllClickablePress = function (e) {
    this.grab(e.getActor());
};

beScript.onAllClickableRelease = function (e) {
    this.ungrab();
};