Although we have not come so far in this course that we have started talking about simulation and animation yet, it is important to bear in mind that when modelling a virtual world, the goal is usually to get the user to suspend disbelief and experience a feeling of presence. the accuracy/realism of the graphics is not necessarily the deciding factor and in many cases pretty images will need to be traded off for rendering speed. You should bear in mind that the behavioural realism of a virtual world is often more important than the graphical realism. If a virtual world behaves realistically then the user will quickly forgive/ignore simple graphics, but a beatifully rendered world that does not behave in a consistent realistic manner will not be so easly forgiven.

A good example of this is computer games. A game with excellent game play and OK graphics will be much more enjoyable than a game with fantastic photorealistic graphics and poor game play.

In 1984, I was a great fan of Elite, a 3D game with simple wireframe graphics. It had great game play so the non-photorealistic graphics were easy to ignore and the player quickly became absorbed in the game, suspending disbelief and becoming a space trader or pirate...