Scripting Question in a CameraScript from racing tutorial

Unity Engine
1

Hi,

I’m currently doing the car tutorial and I have a question for you.

inside the camera’s script:
function LateUpdate () {

  • // Early out if we don’t have a target*

  • if (!target)*

  • return;*

  • // Get the forward direction of the target*
    _ forward = target.TransformDirection (Vector3.forward);_

  • // Get the target position*
    _ targetPosition = target.position;_

  • // Place the camera distance meters behind the target*
    _ transform.position = targetPosition - forward * distance;_

  • // And move the camera a bit up*

  • transform.position.y += height;*

  • // Always look at the target*

  • transform.LookAt (target);*
    }

the forward and targetPosition are something like variables? because it seems to be used like they are.

also, the wantedRotationAngle, wantedHeight, currentRotationAngle, currentHeight etc. in the smooth camera script:

function LateUpdate () {

  • // Early out if we don’t have a target*

  • if (!target)*

  • return;*

  • // Calculate the current rotation angles*
    _ wantedRotationAngle = target.eulerAngles.y;_
    _ wantedHeight = target.position.y + height;_

_ currentRotationAngle = transform.eulerAngles.y;_
_ currentHeight = transform.position.y;_

  • // Damp the rotation around the y-axis*
    _ currentRotationAngle = Mathf.LerpAngle (currentRotationAngle, wantedRotationAngle, rotationDamping * Time.deltaTime);_
  • // Damp the height*
    _ currentHeight = Mathf.Lerp (currentHeight, wantedHeight, heightDamping * Time.deltaTime);_

I understand what is happening in the script but I’m just a little confused about what those terms actually are.

2

You are correct, they are all variables. Since the examples are in JavaScript you don’t have to explicitly declare the type of variable like you have to in C#. In instances where the compiler can “guess” the type, the variables will be statically typed, otherwise there type will be determined at run time. For example

targetPosition = target.position;

targetPosition will be typed as a Vector3 by the compiler (I think :)) since target.posiition returns a Vector3. It could have been typed explicitly like

var targetPosition : Vector3 = target.position;

Here, you are telling the compiler that this variable will be a Vector3. Those that like to do the extra typing tend to go on and on about clarity, runtime errors, blah, blah, blah, or something like that :stuck_out_tongue:

3

Oh, thanx a lot!!!