Unity3d Linerenderer not visible

Question

I am trying to draw a line between two UI GameObjects with Linerenderer. In scene mode everything work fine, but in game mode line is invisible. I tried to change Z position of objects but lines are still invisible. Can anyone help me? Thanks in advance

private LineRenderer lineRenderer;
private float counter;
private float dist;
private Vector3 aPos;
private Vector3 bPos;
public Transform origin;
public Transform destination;
public float lineDrawSpeed = 6f;

// Use this for initialization
void Start()
{
    lineRenderer = GetComponent<LineRenderer>();
    aPos = new Vector3(origin.position.x, origin.position.y, origin.position.z); // Using these to move the lines back
    bPos = new Vector3(destination.position.x, destination.position.y, destination.position.z);

    lineRenderer.SetPosition(0, aPos);
    lineRenderer.SetWidth(3f, 3f);

    dist = Vector3.Distance(origin.position, destination.position);
}

// Update is called once per frame
void Update()
{

    if (counter < dist)
    {
        counter += .1f / lineDrawSpeed;

        float x = Mathf.Lerp(0, dist, counter);

        Vector3 pointA = aPos;
        Vector3 pointB = bPos;

        Vector3 pointAloneLine = x * Vector3.Normalize(pointB - pointA) + pointA;

        lineRenderer.SetPosition(1, pointAloneLine);
    }

}

Answer 1

Unless I'm overlooking some logic error in the code you've posted, I think the problem might be with the material.

Generic debugging help for line renderers:

Try setting the color/material of the line renderer:

lineRenderer.sortingOrder = 1;
lineRenderer.material = new Material (Shader.Find ("Sprites/Default"));
lineRenderer.material.color = Color.red; 

If that doesn't work, perhaps you need to specify the number of vertexes manually?

mineLaser.SetVertexCount (2);

Finally, if these both don't work, it might just be a logic error; try setting the transforms for the lineRenderer's position to be some predefined value and see if it shows up.

For this specific question:

Ah, so its on a canvas. Assuming you mean the UI canvas, I believe linerenderer is the wrong tool to use in this situation. Check out this question.

One of the answers there suggests to:

just use a panel filled with any color you want and use Height and Width to set the length and the Width of your line

Answer 2

This is impossible in "Screen Space - Overlay" Canvas mode. In that mode UI overlay draws on top of everything in Scene (including LineRenderer, that actually non UI element).

Try to use "Screen Space - Camera" option for your Canvas and "Use World Space" option for you Line Renderer.