Dynamically melting snow
The most complex graphics effect in Snowball Earth is without a doubt the snow. As the player walks around and heats up the area around him, the snow melts, forms puddles and finally becomes grass. This is completely dynamic: the player can turn his heating on and off at any point, and the snow reacts correctly to that. The snow even has little piles around trees and rock walls, and these piles lower and disappear when the snow melts. So how did we make this? A slow motion video of how the snow melts around the player. Before I continue, I would like to mention once more that Snowball Earth is Ronimo 's cancelled game from 2008, and that the complete prototype can be downloaded here: Download Snowball Earth prototype (Torrent) So how did I implement this melting effect? The basic trick is that for every vertex, I store the 'meltness': to what extend the ground at that vertex has already been melted. A value of 0 means snow, 0.5 means water and 1 means grass. The pixel shad...