If anyone remembers in Super Mario 64, the goombas were different then their 2D counter parts. Instead of simply walking in a straight line, they actually did some somewhat more dynamic AI. They walked around and when you got close, they suddenly turned toward you and ran at you. This is a very basic AI that can work in a 3D game and today I'd like to show how it can be done.
First off let's break down what kind of behaviours the goomba is using. It uses two simple AI behaviours...
So we know what these behaviours are and they sound pretty simple. Before you just go ahead and make them we need to make sure we have a physics system of some sort. So let's say we have our "Goomba object", well if we want to accurately calculate forces for our AI, we need to make sure he adheres to some form of physics. This physics system is not too complicated, in fact all it needs to consist of for us at this point is the following...
- Velocity (Speed)
You would give your goomba this physics system and give it an update function that applies these forces every frame. With the proper system, simply applying some force, will automatically do all the calculations to make the goomba move. So Force = Mass*acceleration, velocity += acceleration, position += velocity or something of the sort. So this means in our AI behaviours we would be calculating the forced required to go to our target.