- We all know that the value of pi is a constant with a particular immutable value. Anyone who has done any graphical programming also knows that visual rendering relies not just on pi but trigonometry more broadly as well as other mathematical techniques. If we look into the source code of the first person shooter Doom we find that the value of pi used in the game is wrong. In this talk I will explore what happens when we subtly and not so subtly break math in the source.