Raycasting from one object to another - unity3d

Question

I am trying to cast a ray from one object to another but it is not working properly.
Result:
Selected object is "EnemyTank" and ray should point to "PlayerTank" but it is not as you can see.
My code:
void FixedUpdate () {
Vector3 dir = player.transform.position - rayOrigin.transform.position;
RaycastHit hitInfo;
dir = dir.normalized;
Debug.DrawRay(rayOrigin.transform.position, dir*maxCheckDistance,Color.red);
}
player variable points to "PlayerTank"
Playertank location:

Answer 1

So there are a few issues that I can see, but straight to the point:
FixedUpdate Runs on a set interval, it isn't every frame. the Method DrawRay() Has a parameter for duration. by default it is set to 0. This means it will only be visible for a single frame. You have 2 choices you can pass in a duration, or you can put this method in update which does run every frame.
void Update () {
Vector3 dir = player.transform.position - rayOrigin.transform.position;
dir = dir.normalized;
Debug.DrawRay(rayOrigin.transform.position, dir*maxCheckDistance,Color.red);
}
However if you are trying to draw a line from one object to another just use Debug.DrawLine()
Debug.DrawLine(rayOrigin.transform.position, player.transform.position, Color.red);
Lastly, avoid using a color for your line that is the same as one of your objects, I am referring to your red cube, and red line. Use a color that will stand out. Say black in this case.
FixedUpdate example:
void FixedUpdate () {
Vector3 dir = player.transform.position - rayOrigin.transform.position;
dir = dir.normalized;
Debug.DrawRay(rayOrigin.transform.position, dir*maxCheckDistance,Color.red, 1.0f);
}
For fun, to have the line change colors using your maxCheckDistance value:
void Update () {
Color lineColor = color.Black;
if(Vector3.Distance(rayOrigin.transform.position, player.transform.position) < maxCheckDistance) {
lineColor = color.White;
}
Debug.DrawLine(rayOrigin.transform.position, player.transform.position, lineColor);
}
EDIT:
It is important to know where your objects actually are, in your question you have a Player object, that you made the parent of 2 cubes. It appears as though you moved those 2 cubes into where you wanted the player to be in the world instead of moving the Player object itself. So your line is drawing correctly, as it is getting the position to the player object, In the future move the parent object instead of the children object.

Answer 2

From your description and screenshot.
You want to draw ray from "EnemyTank" to "PlayerTank".
and in your code "PlayerTank" is player and "EnemyTank" is rayOrigin.
There has draw a small ray from "EnemyTank" to some other direction. So you definitely miss to define your "PlayerTank" in player object.

Answer 3

The direction parameter in DrawRay is a vector in global space.
Thus your ray always points more or less to the origin.
Sorry, my answer is wrong.