var mouseEventHandler = new MouseEventHandler();
mouseEventHandler.onMouseDoubleClick = true;
mouseEventHandler.onEvent = function (e) {
console.print( "onMouseDoubleClick");
camera = scene.cameras.getByIndex(0);
bb = scene.computeBoundingBox();    
xDist = bb.max.x - bb.min.x;
yDist = bb.max.y - bb.min.y;
zDist = bb.max.z - bb.min.z;
a = 0;
b = 0;
if (xDist > yDist)
    a = xDist;
else 
    a = yDist;
b = a / Math.tan(camera.fov);
dist = b + zDist/2;
if(dist > 2*bb.max.subtract(bb.min).length){
    dist = bb.max.subtract(bb.min).length;
} 
pos = new Vector3(dist*0.5, dist*0.5, dist*0.5).add(bb.center);
camera.targetPosition.set(bb.center);
scene.update();
};
runtime.addEventHandler(mouseEventHandler);