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I have a LineRenderer path to show the path of the GolfBall. Please see in the image, maroon colour path.

enter image description here

private void createTrail()
{
    lineRenderer.SetColors(tracerColor, tracerColor);
    lineRenderer.SetVertexCount(maxVertexCount);
    for (int idx = 0; idx < (maxVertexCount - 2); idx++)
    {//Add another vertex to show ball's roll
        lineRenderer.SetPosition(idx, new Vector3((float)pts[idx * (int)positionSampling].z, (float)pts[idx * (int)positionSampling].y, (float)pts[idx * (int)positionSampling].x));
    }
    lineRenderer.SetPosition(maxVertexCount - 2, new Vector3((float)pts[goal - 1].z, (float)pts[goal - 1].y, (float)pts[goal - 1].x));
    lineRenderer.SetPosition(maxVertexCount - 1, transform.position);
}

The path is drawn using the points in pts[] array.

In repeating the display, I need to clear the old path to redraw the same path again. How can I clear the old path?

derHugo
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batuman
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1 Answers1

10

There is no clear function for LineRenderer and you do not need to clear it in order to redraw it. Also, LineRenderer don't need to be re-drawn manually. This is handle by Unity.

If your goal is to reset old vertex positions you set to it, simply set the LineRenderer's vertex count to 0. You can do this with the SetVertexCount(0) function or positionCount variable. Note that SetVertexCount is now deprecated.

This should remove all the lines you set to the LineRenderer:

LineRenderer.positionCount = 0;

Extension method for this:

public static class ExtensionMethod
{
    public static void Reset(this LineRenderer lr)
    {
        lr.positionCount = 0;
    }
}

Now, you can call lineRenderer.Reset() to reset all the previous positions/path you set to it.

Programmer
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    I think this not works (at least in my case). If you want to keep drawing, as SetVertexCount(0) just set to 0 the old positions, they're still there. So if you want to draw again, you will see that the starting points of the new draw are a little bit random, keeping the reference of the old points. And the LineRenderer will get more positions, the new ones and the old ones, but the latest will already set to 0. – Lotan Apr 04 '18 at 11:21
  • +1 to Lotan's point: setting the positionCount to zero hides the lines, but it doesn't clear out the old state. GetPosition(pos) will still return the old values. – nicb Aug 28 '22 at 20:14