added logic to get accurate pick between utility and main scene
added logic to get accurate pick between utility and main scene

RaananW/Babylon.js,sebavan/Babylon.js,RaananW/Babylon.js,BabylonJS/Babylon.js,RaananW/Babylon.js,BabylonJS/Babylon.js,sebavan/Babylon.js,sebavan/Babylon.js,BabylonJS/Babylon.js