How to draw lines in the Editor?

Questions & Answers
1

I’ve been trying to use the Handle class to draw lines in the editor with no success. I’ve placed the following script in the Assets/Editor folder

using UnityEditor;
using UnityEngine;
using System.Collections;

[ExecuteInEditMode]
public class LineDrawer : MonoBehaviour {

	public void OnSceneGUI()
	{
		Handles.BeginGUI();
		Handles.color = Color.red;
		Handles.DrawLine( Vector3.zero, Vector3.one * 10);
		Handles.EndGUI();
	}
}

I’ve also tried using OnGUI instead of OnSceneGUI. But no line ever shows up in my scene.

3

I don’t think OnSceneGUI is called on Monobehaviours. You need to create a custom Editor for your class and move the OnSceneGUI method there.

Otherwise you can use OnDrawGizmos and Gizmos.DrawLine in your current class.

2

I’ve never used the handles class, but this works for me.

void Update()
{
    Debug.DrawLine(Vector3.zero, Vector3.up, Color.red);
}