Handles.DrawLines

Parameters

Description

Draw a list of line segments.

"Draw multiple lines in sceneview.".

Below is an example of an Editor script that draws lines in SceneView to GameObjects listed in a script.

// Draw lines to the connected game objects that a script has.
// if the target object doesn't have any game objects attached
// then it draws a line from the object to 0,0,0.

using UnityEditor;
using UnityEngine;
using System.Collections.Generic;

[CustomEditor(typeof(ConnectedObjects))]
class ConnectLineHandle : Editor
{
    void OnSceneGUI()
    {
        ConnectedObjects connectedObjects = target as ConnectedObjects;
        if (connectedObjects.objs == null ||
            connectedObjects.objs.Length == 0)
            return;
        // we store the start and end points of the line segments in this array
        Vector3[] lineSegments = new Vector3[connectedObjects.objs.Length * 2];

        int lastObject = connectedObjects.objs.Length - 1;
        Vector3 prevPoint;
        if (connectedObjects.objs[lastObject])
        {
            prevPoint = connectedObjects.objs[lastObject].transform.position;
        }
        else
        {
            prevPoint = Vector3.zero;
        }
        int pointIndex = 0;
        for (int currObjectIndex = 0; currObjectIndex < connectedObjects.objs.Length; currObjectIndex++)
        {
            // find the position of our connected object and store it
            Vector3 currPoint;
            if (connectedObjects.objs[currObjectIndex])
            {
                currPoint = connectedObjects.objs[currObjectIndex].transform.position;
            }
            else
            {
                currPoint = Vector3.zero;
            }

            // store the starting point of the line segment
            lineSegments[pointIndex] = prevPoint;
            pointIndex++;

            // store the ending point of the line segment
            lineSegments[pointIndex] = currPoint;
            pointIndex++;

            prevPoint = currPoint;
        }
        Handles.DrawLines(lineSegments);
    }
}

Example script to attach to a GameObject that will act as a handle:

using UnityEngine;
using System.Collections;

public class ConnectedObjects : MonoBehaviour
{
    public GameObject[] objs = null;
}

Parameters

Description

Draw a list of indexed line segments.

// Draw lines to the connected game objects that a script has.
// if the target object doesn't have any game objects attached
// then it draws a line from the object to 0,0,0.

using UnityEditor;
using UnityEngine;
using System.Collections.Generic;

[CustomEditor(typeof(ConnectedLinePointsObjects))]
class ConnectLinePointsHandle : Editor
{
    void OnSceneGUI()
    {
        ConnectedLinePointsObjects connectedObjects = target as ConnectedLinePointsObjects;
        if (connectedObjects.objs == null ||
            connectedObjects.objs.Length == 0)
            return;

        // we store the points of the line segments in this array
        Vector3[] points = new Vector3[connectedObjects.objs.Length];

        // for each line segment we need two indices into the points array:
        // the index to the start and the end point
        int[] segmentIndices = new int[connectedObjects.objs.Length * 2];

        // create the points and line segments indices
        int prevIndex = connectedObjects.objs.Length - 1;
        int pointIndex = 0;
        int segmentIndex = 0;
        for (int currIndex = 0; currIndex < connectedObjects.objs.Length; currIndex++)
        {
            // find the position of our connected object and store it
            if (connectedObjects.objs[pointIndex])
            {
                points[pointIndex] = connectedObjects.objs[currIndex].transform.position;
            }
            else
            {
                points[pointIndex] = Vector3.zero;
            }

            // the index to the start of the line segment
            segmentIndices[segmentIndex] = prevIndex;
            segmentIndex++;

            // the index to the end of the line segment
            segmentIndices[segmentIndex] = pointIndex;
            segmentIndex++;

            pointIndex++;
            prevIndex = currIndex;
        }
        Handles.DrawLines(points, segmentIndices);
    }
}

And the script attached to this Handle:

using UnityEngine;

using System.Collections;
public class ConnectedLinePointsObjects : MonoBehaviour
{
    public GameObject[] objs = null;
}