Here you will find a method of mines to render the stage. The characters
are inside of a huge stadium so sometimes when it is rendered, as the camera is
close to a character, most of the stage is behind the camera and should not be
drawn. Sometimes a line should be traced betwin a point in front of the camera and
a point behind the camera. All of my calculations in the code seem to handle all
of these cases so there is no trouble in the filiform rendering.