Simple Collisions

• Accurate 3D collision detection of arbitrary objects is a difficult thing to do.
  • I believe that there is still active research in this area.
  • Recent publications
• Fortunately, for most of you Unreal handles this for you.
  • The default objects have onCollisionEvents which you can handle
  • Take a look.
  • Or the default is usually reasonably good.
• My goal is not to do research level, but just gain a basic understanding.
• Circles are by far the easiest thing.
  • Given circle $c_1$ of radius $r_1$ and circle $c_2$ of radius $ r_2$, how can you tell if the two have "collided"?
    • if distance($c_1, c_2$) ≤ $r_1+r_2$
  • Look at a demo
• For this reason, sometimes a system will put everything inside of a "bounding circle".
  • The system does a preliminary bounding circle check
  • If that fails, then a more detailed check is performed.