trigger we simply check the

'Is Trigger' checkbox on the component

settings in the inspector.

When a collider is a trigger things will

no longer bump into it. Instead they will

pass through it and this can be detected

via code.

Similar to normal colliders,

events are called when other colliders

are overlapping with the trigger collider.

In this example we have a box collider

with Is Trigger checked

and a falling 'prop samoflange' ball object.

This object enters the trigger,

stays as it rolls forward and then exits.

To check these events we attach a script

to the trigger, which is registering

OnTriggerEnter and logging to the console

and likewise OnTriggerStay

and OnTriggerExit.

So if we pause the game

and step through one frame at a time,

looking at the console will show that the

object enters the trigger

stays for a number of frames

and eventually exits the trigger.

In the same way as standard collisions,

one of the two objects must have a rigidbody.

It's standard practice to make sure that your trigger

colliders are static objects,

meaning they will not be moved by the

physics engine. So usually you will make

a trigger and then pass a rigidbody

through it. This example is no different.

We're passing our rigidbody object

through the trigger zone and detecting

when something enters that trigger.

So the intention with the trigger collider,

also known as a trigger zone,

is that you can call code without the

objects in your game physically colliding.

So for example, with our hoverpad,

we can add a force to our samoflange ball

to give the effect of it hovering

so long as it stays within the trigger zone.

For example, we could address the object

that's currently staying within the trigger

because the object that's staying

is saved in a variable called 'other'

of type Collider. We could then address

the rigidbody and add a force

in the direction of Vector3.up,

a shortcut for 'up' in world coordinates.

We could then multiply by a number

which we'll save as a variable.

And we'll finish out the AddForce

by choosing acceleration as the mode.

Now we'll move our object over the hoverpad

and we'll use Freeze Position to keep it

in the same place in X and Z.

Allowing the force of Y to create

the hovering effect.

And now if I press play, as you can see

as long as it stays within that area

it creates the effect of hovering without

having to interact without any part

of the geometry.