fix glow layer main determinant with instances
fix glow layer main determinant with instances

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