convert world to screen (crosshair follow)

Question

hi! help with converting in screen coords. I made crosshair following where is muzzle of tank aims. But i can't convert world coord in screen rightly.

 if(Physics.Raycast(firePoint.position, firePoint.TransformDirection(Vector3.left), out hit))
         {
                 Debug.DrawLine(firePoint.position,hit.point,Color.red);
                 
 // Vector 3 of hit.gameobject
                 pointCursor = Camera.main.WorldToScreenPoint(hit.transform.position);
         
        }
 
         void OnGUI()
         {
                 Vector2 vector2 = GUIUtility.ScreenToGUIPoint(new Vector2(pointCursor.x, pointCursor.y));
                 Rect labelRect = new Rect();
                 labelRect.x = vector2.x;                
                 labelRect.y = vector2.y;
                 labelRect.width = cursorTexture.width;
                 labelRect.height = cursorTexture.height;
 
                 GUI.DrawTexture(labelRect,cursorTexture);
         }

Answer 1

You should use hit.point: this returns the 3D point where your raycast hit something. If you use hit.transform.position, the crosshair will be located at the hit object's pivot: looks weird for small objects, and completely wrong for the bigger ones.

...
if (Physics.Raycast(firePoint.position, firePoint.TransformDirection(Vector3.left), out hit)){
  // Use the hit point instead:
  pointCursor = Camera.main.WorldToScreenPoint(hit.point);
}
...

NOTE: The crosshair will be rendered even if the raycast doesn't hit anything, what may seem weird. You can avoid this using a boolean variable like this:

private var hitSomething: boolean; // <- declare this variable

... // assign the raycast result to it: hitSomething = Physics.Raycast(firePoint.position, firePoint.TransformDirection(Vector3.left), out hit); if (hitSomething){ // Use the hit point: pointCursor = Camera.main.WorldToScreenPoint(hit.point); } ...

function OnGUI(){ if (hitSomething){ // only draw the crosshair if something hit: Vector2 vector2 = GUIUtility.ScreenToGUIPoint(new Vector2(pointCursor.x, pointCursor.y)); ... GUI.DrawTexture(labelRect,cursorTexture); } }

convert world to screen (crosshair follow)

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