Simulating Plants and Evolution in the game environment
In this project, 'z' shall be used as up and down. The justification for using 'y', that is so often argued for by OpenGL users, makes little sense. The idea that it is like holding up a paper graph, with 'x' for left/right and 'y' for up/down only makes sense when this graph is an elevation view. It can just as easily be an overhead view. 'x' and 'y' are both lateral directions. 'Depth', just like the physical property of elevation that its name implies, represents vertical displacement.