I want to implement something like this to create a heightmap: 'Place a group of coordinates evenly across a map, and give them height values within a certain range. Repeatedly create coordinates between all of those coordinates, setting their height by deriving a value that was a mean value of all the surrounding coordinates.'
However, I'm not sure how I would go about it - I'm not sure how I could code the part where I place the coordinates in between the existing coordinates. Can anyone give any help/advice?