Unity C＃，面对精灵和刚体的相机无法一起使用

Question

I have a small piece of code to make a sprite (in a 3D world) always face the camera (It has to be in 3D space).

public class CS_CameraFacingBillboard : MonoBehaviour {

    private Camera m_Camera;

    private void Start()
    {
        m_Camera = Camera.main;
    } 

    void Update()
    {
        transform.LookAt(transform.position + m_Camera.transform.rotation * 
Vector3.forward, m_Camera.transform.rotation * Vector3.up); 
    }
}

This code ensures the sprite is always facing the camera, causing it to lean backwards as the camera in above the sprite facing down in a 45 degree agle. When I put a rigidbody on the sprite, the sprite moves on its own towards the direction its leaning. The rigidbody works fine without this code attached.

How can I have a sprite that always faces the camera, and has a rigidbody attached?

Answer 1

It seems you've left the rigidbody as Dynamic , you should set it to Kinematic .

EDIT: After you comments, I checked myself inside Unity, and probably I've recreated the behaviour you described. It happens to me too IF I use a Box Collider on the sprite without locking its rigidbody rotation. So you have three possible solutions:

• Use a Box Collider and under Constraints of the rigidbody freeze the rotation:
• Use a Sphere Collider (or another one that doesn't behave like the box one, you can check them out in play mode).
• Split the components over two game object, a parent and a child. The parent will have all the components except the sprite renderer and the camera script, which will be on the child. This option is the most flexible and less restraining. You can have the box collider without freezing rotations, etc.

Another thing, you can avoid the use of the LookAt method, by simply using:

transform.rotation = m_Camera.transform.rotation;

they have the same outcome.