line renderer 画线

Unity3D 绘制线条的方法可谓多种多样，但是绘制的线条可以在 Game 视图下面显示的方法并不多，本篇通过 Line Renderer 方法绘制可以在 Game 视图下面显示的线条。原文链接：http://www.everyday3d.com/blog/index.php/2010/03/15/3-ways-to-draw-3d-lines-in-unity3d/。

新建立一个 C# 脚本，取名：DrawLinesByLineRender.cs 代码如下：

001using UnityEngine;

002using System.Collections;

003 

004public class DrawLinesByLineRender : MonoBehaviour {

005 

006    public Shader shader;

007 

008    private Vector3 curr;

009    private Vector3 last = new Vector3(0,0,-100.0f);

010     

011    private int canvasIndex = 0;

012    private float lineSizeLarge = 0.02f;

013    private float lineSizeSmall = 0.02f;

014     

015    private Color lineColorLarge = new Color(0,0,0,0.5f);

016    private Color lineColorSmall = new Color(0,0,0,0.1f);

017     

018    private ArrayList points;

019     

020    GUIStyle labelStyle;

021    GUIStyle linkStyle;

022     

023    private float speed = 100f;

024 

025    void Start () {

026        labelStyle = new GUIStyle();

027        labelStyle.normal.textColor = Color.black;

028         

029        linkStyle = new GUIStyle();

030        linkStyle.normal.textColor = Color.blue;

031         

032        points = new ArrayList();

033    }

034     

035    void OnGUI() {

036        GUI.Label (new Rect (10, 10, 300, 24), "LR. Cursor keys to rotate (with Shift for slow)", labelStyle);

037        int vc = canvasIndex + points.Count;

038        GUI.Label (new Rect (10, 26, 300, 24), "Drawin " + vc + " lines. 'C' to clear", labelStyle);

039         

040        GUI.Label (new Rect (10, Screen.height - 20, 250, 24), ".Inspired by a demo from ", labelStyle);

041        if(GUI.Button (new Rect (150, Screen.height - 20, 300, 24),"mrdoob", linkStyle)) {

042            Application.OpenURL("http://mrdoob.com/lab/javascript/harmony/");

043        }

044    }

045     

046    void Update () {

047        float sp = speed * Time.deltaTime;

048        if(Input.GetKey(KeyCode.RightShift) || Input.GetKey(KeyCode.LeftShift)) sp = sp * 0.1f;

049        if(Input.GetKey(KeyCode.UpArrow)) transform.Rotate(-sp, 0, 0);

050        if(Input.GetKey(KeyCode.DownArrow)) transform.Rotate(sp, 0, 0);

051        if(Input.GetKey(KeyCode.LeftArrow)) transform.Rotate(0, -sp, 0);

052        if(Input.GetKey(KeyCode.RightArrow)) transform.Rotate(0, sp, 0);

053         

054        if(Input.GetKeyDown(KeyCode.C)) {

055            points = new ArrayList();

056            foreach (Transform line in transform) {

057                GameObject go = line.gameObject;

058                Destroy(go.GetComponent(typeof(LineRenderer)));

059                Destroy(line);

060            }

061        }

062         

063        if(Input.GetMouseButton(0)) {

064            curr = Camera.main.ScreenToWorldPoint(newVector3(Input.mousePosition.x, Input.mousePosition.y, Camera.main.transform.position.z * -1.0f));

065            curr = transform.InverseTransformPoint(curr);

066 

067            if(last.z != -100.0f) {

068                createLine(last, curr, lineSizeLarge, lineColorLarge);

069                 

070                foreach(Vector3 p in points) {

071                    Vector3 s = p;

072                    float d = Vector3.Distance(s, curr);

073                    if(d < 1 && Random.value > 0.9f) createLine(s, curr, lineSizeSmall, lineColorSmall);

074                }

075                 

076                points.Add(curr);

077            }

078             

079            last = curr;

080        } else {

081            last.z = -100.0f;

082        }

083         

084         

085    }

086     

087    private void createLine(Vector3 start, Vector3 end, float lineSize, Color c) {

088        GameObject canvas = new GameObject("canvas" + canvasIndex);

089        canvas.transform.parent = transform;

090        canvas.transform.rotation = transform.rotation;

091        LineRenderer lines = (LineRenderer) canvas.AddComponent<LineRenderer>();

092        lines.material = new Material(shader);

093        lines.material.color = c;

094        lines.useWorldSpace = false;

095        lines.SetWidth(lineSize, lineSize);

096        lines.SetVertexCount(2);

097        lines.SetPosition(0, start);

098        lines.SetPosition(1, end);

099        canvasIndex++;

100    }

101}

新建立一个空对象，然后把 DrawLinesByLineRender.cs 组件挂载到空对象上，如图：

运行游戏，最终效果如图：