Question Observing the direction of an gameobject

Hi, I am struggling on understanding on how transform works.

There are multiple transform(cars) stored in a list, with another list tracking each transform checkpoint count.

Below is a describing a method that gathers the nextcheckpoint of the current transform, and attempts to gather the forward direction.

Code (CSharp):

1.     public override void CollectObservations(VectorSensor sensor)
2.     {
3.         Vector3 checkpointForward = trackCheckpoints.GetNextCheckpoint(transform).transform.forward;
4.         float directionDot = Vector3.Dot(transform.forward, checkpointForward);
5.         sensor.AddObservation(directionDot);
6.     }

Code (CSharp):

1.     public void GetNextCheckpoint(Transform carTransform)
2.     {
3.         int nextCheckpointSingleIndex = nextCheckpointSingleIndexList[carTransformList.IndexOf(carTransform)];
4.  
5.     }

With this implementation I get
Operator '.' cannot be applied to operand of type 'void'

If someone could lead me to the right direction that would be appreciated

 

The error message should tell you which code file the error is in. After the error message there are two numbers in parentheses. The first number is the line of code where the error is supposed to be, the second number is the exact character. Once you find that it should be pretty easy to spot the error.

I think maybe you are attempting to access a return value of a method that does not return a value.

 

Specifically, you're doing

Code (csharp):

1. GetNextCheckpoint(transform).transform ...

When clearly GetNextCheckpoint returns void (in the next codeblock) and you can't access transform from void. Void is nothing.

 

So the function method does not have a return because it is a void. Does not return. But you ask for something to = a function that does not return.