Text Rain, or Chinese Snow.
Finished in Processing. Having captured the video from the camera, I used brightness to distinguish human/objects and background. The characters will fall down as long the brightness of the pixel postion is bigger than a value.

Here’s code link: https://github.com/mengs/qiangJingJiu

PS:
There will be very English rainy, so I chose one of my favorite Chinese Poem by Li bai.