FlapPyBird 3: stack consecutive frames

Stack up consecutive frames will let the neural network detect motion. This will be important for the network to know which direction Flappy Bird is moving, and how fast.
This video is part of a playlist, • FlapPyBird RL .
The code for this video is available under MIT license at github.com/hug... (this contains. a few more changes, from future videos, unfortunately...) .