Sprite as bullet

[Kolkina]

I have a sprite that I want to use for a bullet in 3d space and I want it to constantly face the players transform (sort of like the monsters in doom always look at you).

I’ve tried attaching my sprite to a plane, but I can’t seem to figure out how to move it in world space.

I don’t want to have to use InverseTransformDirection for each frame, since I’m expecting to have a lot of bullets, so I would like to have the movement vector planned out during the start function.

Is there some other, better way to use an image as a bullet ? If not, how would I make my plane always rotate towards the player, while still moving the same direction in world space?

[whydoidoit]

So a plane draws it’s visible face upwards - to billboard you need to point that upwards face in the opposite direction to Camera.main.transform.forward.

Your bullet script will need a direction in it as you can’t use it’s rotation because that’s dependent on the viewing angle.

   Quaternion rotateUpToForward = Quaternion.FromToRotation(Vector3.up, Vector3.forward);
   public Vector3 bulletDirection;
   public float speed;

   static Transform mainCameraTransform;
   void Start()
   {
       mainCameraTransform = Camera.main.transform;
   }
   
   void Update()
   {
         transform.position += bulletDirection * speed;
         transform.forward = rotateUpToForward * -mainCameraTransform.forward;
   }

I wrote a tutorial on Quaternions over on Unity Gems covers a lot of this stuff