Stealth game tutorial - 107 - CCTV Cameras - Unity Official Tutorials

Now we will add one of the systems that

triggers the alarm in our game,

the CCTV cameras that are trying to spot the player.

The first step is to drag the model in

to the scene and to position it on the battle bus.

In the Models folder locate prop_cctvCam.

It should look like this. Drag it in

to the hierarchy and then position it at

(-8, 3, 16.1).

This will place it on the battle bus

but it needs rotating by 180 in the Y axis.

Select it in the hierarchy and with

your mouse cursor over the scene view

press F to focus on it.

Make sure to check the Use Light Probes

box on the mesh renderer on each of the

game objects in the camera hierarchy

so that the camera has dynamic light shining on it.

As you can see it's now properly lit.

Light probes have been setup for you

and are part of the Lights prefab that we

created earlier.

The next thing our CCTV camera needs

is a frustum. We want to start by adding

the collision mesh to the camera.

When the player is detected within this frustum

the alarm will sound.

We want to start by adding the collision mesh

to the camera. We need to make it a

child of the camera body.

In the Models folder locate prop_cctvCam_collision.

Drag and drop this on to prop_cctvCam_body

in the hierarchy.

We need to reposition it slightly.

The frustum should appear to be coming

from the lens. Set the position of this object

to (0, 0.15, 0.35).

The purpose of this game object is to show

where the camera is pointing and to detect

the player when he is in front of the camera.

To physically detect the player we're going

to use a trigger collider. Add a mesh

collider to the collision object that we

just added. Click the Add Component button

and choose Physics - Mesh Collider.

Then check the box for Is Trigger.

The frustum looks a little poor at the moment

so instead we're going to use a spot light

to show where the camera is pointing

and remove the unnecessary visual

components from the game object.

Remove the mesh filter by clicking on the

cog to the right of it, and choose Remove Component.

Do the same for the mesh renderer.

Before we create any visual effects

we want the camera to be pointing in the right direction.

We want to prevent the player from passing

through this space when the camera is facing

forward. So to completely cover the area

we're going to tilt the camera body

60 degrees in the X axis.

Select prop_cctvCam_body

and in the X axis for rotation

put in 60 degrees.

To visually represent the frustum we're going

to add a spotlight to it.

Reselect prop_cctvCam_collision

then go to Add Component - Rendering - Light.

Change the type to Spot.

Set the range to 9.5,

the angle to 90,

the colour to red.

We'll set the shadow type to Hard Shadow

with a bias of 0.02.

We don't want this light baked in if

we rebake the light map later.

So we need to set the light mapping setting

to Real Time Only.

This looks okay, but to improve the effect

we're going to add a cookie to the light.

A cookie is effectively a texture that

your light projects. The one we're going to

use is in the Textures folder and is called

FX_cameraview_ALP.

Drag and drop this on to the cookie

property of the light

and you should see a starlight pattern

projected on the floor. Now we need to make

a script to report the location of the player

when he's spotted by the CCTV camera.

We'll call it CCTVPlayerDetection

Click the Add Component button

and choose New Script and name it

CCTVPlayerDetection. Click Create and Add

and then double click the icon

to launch it for editing.

Remove the default functions and setup

your script for use. For this script we'll

need a couple of private class variables

to store references.

Firstly to the player so that we know it's

the player that we've detected.

Secondly we need a reference to the last

player sighting script on the game controller.

So that we can update the position variable

when we need to.

We will now use the Awake function to

allocate these references.

We can allocate the player reference using

FindGameObjectWithTag and parsing

the Player variable from our tag script.

We can also find the game controller

in the same way. We then need to use

GetComponent afterwards to get a reference

to the last player sighting script

on the game controller.

Now we're going to use OnTriggerStay

to detect the player.

Given that a collider will be detected

within the trigger zone, we want to check if

the game object belonging to that collider

is the player.

We need to be careful at this point.

It could be that our player is on the other

side of a wall but still

intersecting the collider.

To resolve this we're going to

raycast from the lens of the camera

to the player to check the line of sight.

We'll start by finding the relative position

of the player from the camera

so that we have a direction to raycast in.

We will also need a raycastHit variable

to determine whether or not the raycast

intersects the player collider.

Using these we can raycast from the

camera towards the player and get back

information on what the raycast hits.

Next we need to check whether the game object

of the collider of whatever we hit

was the player.

If it was then we want to update the game

controller with the last sighting of the player.

This concludes the CCTV player detection script

so we need to save it and return to the editor.

At this point we want to drag our CCTV

camera in to the Prefabs folder

to save it as a prefab.

We can then duplicate this around our level

to make more cameras. Select the parent

prop_cctvCam and drop it on to the

Prefabs folder in the project panel.

Now let's duplicate this camera twice

for our other cameras in the scene.

We now have three in the same place.

Let's position one of them at (-21, 2.2, 2).

Then reselect it in the hierarchy and

press F to focus on it.

You should see that this is now on one

of the buildings in the lower left

of the game.

Now select one of the other CCTV cams

and place it at (-23, 1.8, 24).

Reselect it in the hierarchy and press F

with your mouse over the scene view to focus on it.

You should see that it's now on the wall

of the security department building

in the centre of the map.

This camera needs to spot the player coming

through the break in the fence.

So we will tilt it up in the X axis

in order to face the fence.

Drill down in to this object and select

prop_cctvCam_body

and set the rotation of X from 60

to 30. Select prop_cctvCam_collision.

We also need to lengthen the trigger

collider so that it reaches the fence.

So change the scale to (1, 1, 1.8).

We want the camera on the battle bus to be

animated, so we will return to working

on this camera now.

Reselect it and focus on it.

We want the camera on the battle bus to

be animated. But before we do this

we can notice that the intensity of the

spotlight is not enough.

This is the power of prefabs in Unity.

Because we now want to update all three

cameras with a brighter intensity

we can drill down in to any one of them.

Select prop_cctvCam_collision

and change the intensity.

Set it to a value of 4 and press return.

Then hit the apply button.

This saves the change out to the prefab

and now when we check our other cctv cams

we can see that they have a brighter intensity too.

Now let's animate our camera.

This camera should sweep back and forth.

We do this by creating a new animation asset.

Select the Animation folder in the project panel.

Click the Create button and choose Animation.

Call the animation cctv_sweep.

Now expand the prop_cctvCamera

and select prop_cctvCam_Joint.

Drag and drop this animation asset

on to the object in the inspector.

This adds an animation component

and assigns this asset as the animation to play.

Now we need to open up Unity's animation

window. Go to Window - Animation.

We will dock this, along with our game

view at the bottom.

This allows us to see the animation we are doing

in the scene view and work on the animation

at the same time. We want the camera

to rotate around the Y axis.

So we will click on Rotation.Y and select Add Curves.

To the right of Rotation.Y

click and choose Add Curves from the menu that appears.

This will add rotations as curves on the

graph and gives a keyframe at the start

of the animation. We want the animation

to last about 2 seconds so we will add

another keyframe there.

Scrub the playhead to 2 seconds

and click the Add Keyframe button at the

top of the animation window.

Now set the value to 60.

All that's left to do is to make sure that

our animation loops. We do this by

changing the wrap mode at the bottom,

which is currently set to default.

Change this to Ping Pong.

This means that our animation will go from

0 to 60 and then head back to 0 in an infinite loop.

This completes the creation of our animation

and we can test it by pressing the play button

at the top of the interface.

You should note that when our camera is

rotated there is a gap around which

the player can sneak.

This concludes the creation of our CCTV camera

and the end of this assignment.

In the next assignment we will look at

creating laser gates, which are designed to

detect the player also.

Remember to save your scene

and save the project before moving on.