Hi blenderheads!
I am working on a christmas scene. (already) 
This is my model. (Textures are coming later!)
Now, I want light trays from the window.
What is the easiest way to do it?
Please help me!
You’ll need to either put texture mapped planes where you want the rays to be, or grab a volume build of Blender (DingTo’s branch) and play around with that. Light rays are caused by light scattering through a medium.