Unity3d 广告牌效果

旋转物体始终面向摄像机, Scene和Game 场景中都可以使用, 

直接使用LookAt(...)方法的话会有问题,物体面向摄像机的同时会绕Z轴旋转, 解决方法就是改为, 不是面对摄像机而是面对摄像机所在的平面.

/// 始终面向摄像机
/// 
public class SimpleBillboard : MonoBehaviour
{
    public bool IsStopInSceneView = false;
    void OnDrawGizmos()
    {
        if (IsStopInSceneView == false && Application.isPlaying == false && SceneView.currentDrawingSceneView.camera != null)
        {
            Rot(SceneView.currentDrawingSceneView.camera.
                transform);
        }
    }

    void Update()
    {
          Rot(Camera.main.camera.transform);
    }

    void Rot(Transform target)
    {
        Plane plane = new Plane(target.forward, target.position);
        float dis;
        Vector3 tar = target.position;
        if (plane.Raycast(new Ray(this.transform.position, -target.forward),out dis) == true)
        {
            tar = this.transform.position + (-target.forward * dis);
        }
        this.transform.LookAt(tar, Vector3.up);
    }
}