Game Design and Artificial Intelligence - Bournemouth University

Game Design and Artificial Intelligence
David Hopkins
fig 2.3 – The bridge of the ship with the player character and the AI pilot
Space Combat
The space Combat was where most effort was based during the production of this project. For the
demo, all though there was not enough time to implement a three dimensional version, it was
possible to work on a two dimensional approach, with an x and y axis. Three attempts were made at
producing the AI for the ships. The first experiment was creating a ship that would follow a target
around. This was done by calculating the distance between the ship and the target in both x and y
axis, calculating the angle between them and adding a velocity based on the angle. Much of this
was taken from my previous programming project from last year, as this used the same theory to
have an object always look towards a target. However there was a drawback with this. The ships
could only rotate 360 degrees. Once the angle reached over 360 degrees, the object would have to
rotate all the way round the other way as the object believes the angle to be a small value (as the
value over 360 would then switch to 0). This method required some tweaking which would allow
the object to follow an object by rotating around the quickest way. The way this was solved, was
through working out the difference between the current ship rotation and the desired angle. If this
difference is less than and absolute value of 180 degrees, the ship can rotate based on whether angle
is smaller or larger. However if the difference is bigger than 180, then we have to reverse this
situation as the target has gone full circle. This took a while to discover, but it is fairly effective.
if((rotation­angle)>180)
{
if((rotation­angle)>0)
rotation+=(70.0*TIMER);
}
if((rotation­angle)