Potential way to improve terrain rendering

[pengzhenghao]

See: https://www.reddit.com/r/proceduralgeneration/comments/cor8zg/lightworld_improved_terrain_and_water/

and this repo: https://github.com/BeanOfLight/Lightworld/tree/f247e81979c71469d1afed35f0ccacf7c0760592

The effect is quite well!

[pengzhenghao]

The terrain, namely the repeated flat grass land image, seems to be very boring and ugly. So we need to improve this if we wish to use RGB to train real agents!