Basic Hit Detection In Unity

Hit detection is pretty fundamental to any video game. Fortunately, Unity makes hit detection easy, with the use of colliders. To get started, just add any Collider component to a GameObject and set its size to fit whatever your visual element is. Next, you may want to set the “Is Trigger” flag, since in this case, you are purely using your collider for hit detection. Since you can attach a Collider to any object, you can do fancy things like moving and resizing it dynamically based on game logic or as part of an animation, depending o your application.

Once you have your Collider created, the next step is to add a RigidBody component, to make sure your script can listen for collisions. Note that anything you want to hit also needs a Collider but doesn’t need a RigidBody, unless it also has a script that needs to listen for collisions.

Getting into scripting, it is pretty easy to listen for collisions. All you need is a method called OnTriggerEnter or OnTriggerEnter2D, which will automatically be called whenever your Collider hits something. Filtering down to what you hit is also easy since this method gets passed in the collider it hit. You can then check the name or tag of this object, or use any other method of figuring out if it is the one you were looking for.