DrawLine with GL

DrawGLLine.cs

using UnityEngine;

public class DrawLine : MonoBehaviour
{
    Color lineColor = Color.red;
    float distance = 100;
    Material lineMaterial;

    void CreateLineMaterial()
    {
        if (!lineMaterial)
        {
            // Unity has a built-in shader that is useful for drawing
            // simple colored things.
            var shader = Shader.Find("Hidden/Internal-Colored");
            lineMaterial = new Material(shader);
            lineMaterial.hideFlags = HideFlags.HideAndDontSave;
            // Turn on alpha blending
            lineMaterial.SetInt("_SrcBlend", (int)UnityEngine.Rendering.BlendMode.SrcAlpha);
            lineMaterial.SetInt("_DstBlend", (int)UnityEngine.Rendering.BlendMode.OneMinusSrcAlpha);
            // Turn backface culling off
            lineMaterial.SetInt("_Cull", (int)UnityEngine.Rendering.CullMode.Off);
            // Turn off depth writes
            lineMaterial.SetInt("_ZWrite", 0);
        }
    }


    // cannot call this on update, line not visible then.. and OnPostRender() works on camera only
    void OnRenderObject()
    {
        CreateLineMaterial();
        lineMaterial.SetPass(0);
        GL.PushMatrix();
        GL.MultMatrix(transform.localToWorldMatrix); // not needed if already in worldspace
        GL.Begin(GL.LINES);
        GL.Color(lineColor);
        GL.Vertex3(transform.position.x, transform.position.y, transform.position.z);
        GL.Vertex3(transform.position.x + transform.forward.x * distance, transform.position.y + transform.forward.y * distance, transform.position.z + transform.forward.z * distance);
        GL.End();
        GL.PopMatrix();
    }
}