ScreenToWorldPoint for different ortographic size

Questions & Answers
1

I need to calculate world point from screen coordinates for orthographic camera. Normally I would use Camera.ScreenToWorldPoint method and be happy with it, but I need to calculate this point for camera with ortographic size different from current one. How would I go about this?

Here is exactly what my problem is in case I’m overthinking and there is a simpler solution.

  1. I have a point in world space.
  2. I have a square on UI with it’s upper-left corner “connected” to world space point
  3. I want to move my camera so center of that point is in the middle. Easy one, I calculate world position for that center and I move my camera there.
  4. I want to change the camera to some orthographic size (that I know beforehand) while it’s moving.
  5. Problem: when I’m changing the size there is some offset created and world position I calculated beforehand is no longer valid
2

As per usual, right after I posted the question I suddenly got like 5 ideas how to solve it. I will leave the answer here in case someone comes looking for it.

Basically I divided my point into two parts:

  1. World space position of the corner (which I already had)
  2. Offset from the corner to center in screen space units

Next step was to convert my offset from screen space to world space units. As I have an orthographic camera it was pretty easy. Basically the code boiled down to this:

        float cameraVertical = targetOrthographicSize * 2;
		float cameraHorizontal = cameraVertical * camera.aspect;

		offset = new Vector2(offset.x * (cameraHorizontal / Screen.width), offset.y * (cameraVertical / Screen.height));
		MoveCamera(worldPosition + offset);