How can I draw a line of certain length and direction?

Question

I want to create a line of certain length and direction.

What I mean by this is drawing a line from Point A to Point B. Normally in Unity C# to draw a line from Point A to Point B is simply:

Debug.DrawLine(point_A, point_B);

The diagram would be something like this

A----------------B

But I dont want something like this, I want it to draw from Point A to Point B but with a certain length. So I am guessing I need the direction for this to work. But I don't know how to code it.

Here is a basic diagram of how i want it.

A--------        B

Answer 1

You can simply get the vector pointing in the right direction, then scale it by the distance you want and add that to the initial point. This will define a new end point for your line.

//Get the direction of the line
Vector3 direction = point_B - point_A;
//Get a new point at your distance from point A
Vector3 point_C = point_A + (direction.normalized * distance);
//Draw the line
Debug.DrawLine(point_A, point_C);

Answer 2

If you know the start and end points as well as the desired length, you can use Vector3.Lerp

Vector3 midPoint = Vector3.Lerp(startVector, endVector, 0.5f);

Debug.DrawLine(startVector, midPoint);