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You have completed Unity Basics!
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Let’s learn how to detect when the player hits a pipe obstacle.
Unity 6 Documentation
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Okay, so the last bit of core logic
we need to implement
0:01
is handling the player
hitting a pipe and losing their run.
0:03
This means that in our code,
we need to detect
0:08
when the player collides with something.
0:10
But the player can also collide
with the ground and our invisible player
0:12
bounds up top,
0:15
so we need a way to make sure it's a pipe
that they're colliding with.
0:17
There are numerous ways to do this,
but the most simple way I know of
0:20
is using tags.
0:24
It's also not as taxing
on your performance as other options.
0:25
Tags in Unity are just labels
you can assign to game
0:29
objects
for easy identification and grouping.
0:32
If we select a game object
in our hierarchy and look just beneath
0:35
the name field up top, you'll see
a tag option with a drop down menu.
0:39
There are some default tags we can use,
but we have the ability to create our own
0:43
as well.
Let's do that by selecting Add Tag.
0:47
This opens a menu for tags and layers.
0:50
As mentioned, tags are just text labels
for identifying objects.
0:53
Sorting layers determine the order in
which sprites are rendered to the camera.
0:58
Layers are regarding physics
and rendering layers are used by cameras
1:02
and lights to determine what gets rendered
1:06
but we won't need to worry
about those in this course.
1:08
Under the empty tags
1:11
list, let's click this plus icon
to add a new one, name it Pipe,
1:12
and hit enter. Now similar to the input
button earlier, this is case sensitive,
1:16
so it needs to be spelled and capitalized
exactly the same in our code.
1:21
And don't worry, this didn't add
1:25
this new tag to our game object
that we had selected.
1:27
We could have assigned the player
tag to our player object,
1:30
but I wanted to show you that process
of creating a new tag
1:33
and the following process
of editing a prefab.
1:36
So as mentioned before,
in order to edit a prefab,
1:39
we find it in our project window
and double-click it.
1:42
This changes the hierarchy and inspector
windows to our prefab editor,
1:45
and now we can make changes to it
1:49
that will carry over to all future pipes
that we instantiate.
1:51
Let's select both of our individual pipe
children objects by holding
1:55
shift and clicking them.
1:59
We want the tags to be on these
and not the parent
2:01
because these individual pipe objects
have the colliders attached to them.
2:04
Now open the tag dropdown
and select our new pipe tag
2:08
Now to go back to the normal editor
we click this tiny little left
2:14
facing arrow at the top here.
Perfect!
2:18
Let's now open our Player script.
2:21
Unity has an awesome built-in
method for detecting collisions.
2:27
So beneath our Update method here,
but still inside our class,
2:30
let's start typing OnCollisionEnter2D.
2:34
Again,
make sure you select the 2D version.
2:38
This method will get called
2:42
every time our player collides
with another collider in the game.
2:43
It also automatically receives data
about the collision
2:47
and the other collider involved.
2:50
By default, Unity named this collision,
but typically you'll see people
2:52
rename it to other, which makes things
a bit more clear, so let's do that.
2:57
So we
need to ensure that this other collider
3:02
belongs to a game object
that has the pipe tag, right?
3:05
Right.
3:08
Sounds a good place
for a conditional statement.
3:09
We can do this by typing if other
3:13
dot game object, with that
lowercase g again. And now, instead
3:18
of the other collider, we're referencing
the game object it's attached to.
3:22
Now that we have the game object itself,
we can check its tag property.
3:27
So we can say .CompareTag.
3:31
If we hover over this,
it states returns true
3:36
if the game object has the given tag,
and it requires a string of the tag name.
3:39
So, within the parentheses, let's put our
quotes for the string and provide pipe.
3:45
Mine had a capital P,
make sure yours is just how you wrote it
3:50
when creating the tag.
3:53
In our block,
3:57
let's Debug.Log a message
letting us know it's working.
3:58
Save and head back to Unity to test.
4:06
If I immediately hit the floor,
4:15
we don't see a message,
but the moment I hit a pipe, we get it.
4:17
Perfect.
4:20
So we know we're ready
to add our losing logic.
4:21
Let's handle that in the next video.
4:24
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