Unity3d LineRenderer畫線

1、  畫多條線

畫多條線需要在場景中放置多個GameObject，因為一個GameObject只能添加一個LineRenderer Component。

2、  線段樣式

線段的樣式由LineRenderer組件的材質控制

3、  坐標系

LineRenderer使用了2種坐標系:World和Location。在設置目標點的時候需要注意你使用的坐標系是哪一種。

Location:

transform.LookAt(rh.point);  //GameObject始終面對目標點
lineRenderer = (LineRenderer)gameObject.GetComponent ("LineRenderer");     
       lineRenderer.useWorldSpace=false;
       lineRenderer.SetWidth(0.1f,0.1f);
　　　　Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
            if(Physics.Raycast(ray,out rh)){
　　　　　　　　　　lineRenderer.SetPosition(0, Vector3.forward*rh.distance);//方向*距離，典型的Location坐標系用法
　　　　　　　　}

World:

void Start () {
        gameObject.SetActive(false);
        lr = gameObject.GetComponent(typeof(LineRenderer)) as LineRenderer;            
        lr.SetWidth(0.1f,0.1f);
    }
    
    // Update is called once per frame
    void Update () {    
        if(Input.GetMouseButtonUp(0)){
            
            //Get click position
            Ray ray = Camera.mainCamera.ScreenPointToRay(Input.mousePosition);
            lr.SetVertexCount(lineSeg+1);
            if(Physics.Raycast(ray,out rh)){                
                pointPos.Add(DrawLine(rh));
            }            
        }
        
        if(Input.GetMouseButtonUp(1)){
            //destroy point
            DestroyLine();
        }
        
        
    }
    
    
    GameObject DrawLine(RaycastHit pointPos){

                //Display point
                GameObject gb_pointer = GameObject.Instantiate(pointer) as GameObject;
                gb_pointer.transform.position =pointPos.point + (transform.position - pointPos.point) * 0.01f; 
                gb_pointer.transform.rotation = Quaternion.LookRotation (pointPos.normal, Camera.mainCamera.transform.up);
                Vector3 laserpos = new Vector3();
                laserpos.x= 90.0f;
                laserpos.y= gb_pointer.transform.position.y;
                laserpos.z= gb_pointer.transform.position.z;
                gb_pointer.transform.eulerAngles = laserpos;
                lr.SetPosition(lineSeg,pointPos.point);   //設置目標點的坐標，使用的是world坐標系
                lineSeg++;
                return gb_pointer;
    }
    
    void DestroyLine(){
    
        int arrayLength = pointPos.Count;
        if(arrayLength > 0){
            GameObject.Destroy(pointPos[arrayLength-1]);
            pointPos.RemoveAt(arrayLength-1);        
            lr.SetVertexCount(--lineSeg);
        }
    }