How do I draw dotted lines?

Scripting
1

I have problem…

I need to draw dotted line when mouse click and drag it.

DrawLine function can only draw straight line…

static function DrawLine (start : Vector3, end : Vector3, color : Color = Color.white) : void

what is the best way to accomplish this?

Thanks in advance.

2

A line renderer might do the job quite nicely. You need to use a wide texture with the dots drawn on it horizontally.

3

Had to do the same thing in Unity 2019.3. Even though the TextureMode field exists on the LineRenderer, I was not able to figure out the correct math for not distorting the dots. So, I went with TextureMode set to Stretch. On the texture that I used as the dot on the line, I set WrapMode to Repeat. Edited the texture in PS to add some padding to spread the dots apart from each other (Canvas Size in PS). Created a material with this texture. Used the shader Mobile/Particles/AlphaBlended.

Here’s a script that I used on my dotted line prefab (attached to the same object that has the LineRenderer component)

using UnityEngine;
public class DottedLineRenderer : MonoBehaviour
{
     public bool scaleInUpdate = false;
     private LineRenderer lR;
     private Renderer rend;
     private void Start ()
     {
         ScaleMaterial();
         enabled = scaleInUpdate;
     }
     public void ScaleMaterial()
     {
         lR = GetComponent<LineRenderer>();
         rend = GetComponent<Renderer>();
         rend.material.mainTextureScale =
             new Vector2(Vector2.Distance(lR.GetPosition(0), lR.GetPosition(lR.positionCount - 1)) / lR.widthMultiplier,
                 1);
     }
     private void Update ()
     {
         rend.material.mainTextureScale =
             new Vector2(Vector2.Distance(lR.GetPosition(0), lR.GetPosition(lR.positionCount - 1)) / lR.widthMultiplier,
                 1);
     }
}

Another issue that I’ve encountered - I wanted to fade the start and end of the line into transparency by setting the color gradient on the line. For some reason this did not work for me if the line had only 2 points and both ends were transparent, but it did work when the line had more than 2 points. Here’s the code that I used to resolve this and add more points to the line:

// line renderer with 2 points only does not handle transparency properly:
         lineRenderer.positionCount = linePointsCount; // I used linePointsCount = 10
         for (var i = 0; i < linePointsCount; i++)
         {
             lineRenderer.SetPosition(i,
                 Vector3.Lerp(fromPoint, toPoint, (float) i / (linePointsCount - 1)));
         }
        
         var dottedLine = lineObject.GetComponent<DottedLineRenderer>();
         if(dottedLine != null) dottedLine.ScaleMaterial();

I hope this helps someone.