After Effects Sunshine

In one of the shorter scenes, I need to create the illusion of the sun shining through a window, and the rays illuminating the room that the protagonist stands in. I thought the best way to create this effect would be with Adobe After Effects. I found a great YouTube tutorial online by searching 'After Effects sun ray light.' What came up was a Text animation tutorial, but I applied the knowledge learnt through it to using on my image.
http://www.youtube.com/watch?v=6-X999qybnM&list=PL06BB622B5353ACA2&index=4

I had earlier created a sky scene using PhotoShop. To animate the sun separate of the background, I saved them as two different PS layers.

I imported both the layers into a new After Effects composition which had the same dimensions as the final piece I want to create. I followed the tutorial's instructions and created a double layer of the sun, and gave both of them the 'fast blur' effect of different amounts. Then, on the underlying sun layer, I added another effect called 'CC radial blur.' I created a keyframe at the 0 second mark, and another at the 3 second mark when I had adjusted the amount of the effect from 0 to 230. It took quite a while to render out the scene, but I managed to create a quick, simple animation of a sun shining brightly with increasing intensity.