UnityEngine.Camera.ViewportToWorldPoint C# (CSharp) Method

        public Vector3 ViewportToWorldPoint(Vector3 position)
        {
            Vector3 vector;
            INTERNAL_CALL_ViewportToWorldPoint(this, ref position, out vector);
            return vector;
        }

        public static Vector2 GetScreenSizeInWorldCoords(Camera gameCamera, float distance = 10f)
        {
            float width = 0f;
            float height = 0f;

            if (gameCamera.orthographic)
            {
                if (gameCamera.orthographicSize <= .001f)
                    return Vector2.zero;

                var p1 = gameCamera.ViewportToWorldPoint(new Vector3(0, 0, gameCamera.nearClipPlane));
                var p2 = gameCamera.ViewportToWorldPoint(new Vector3(1, 0, gameCamera.nearClipPlane));
                var p3 = gameCamera.ViewportToWorldPoint(new Vector3(1, 1, gameCamera.nearClipPlane));

                width = (p2 - p1).magnitude;
                height = (p3 - p2).magnitude;
            }
            else
            {
                height = 2.0f * distance * Mathf.Tan(gameCamera.fieldOfView * 0.5f * Mathf.Deg2Rad);
                width = height * gameCamera.aspect;
            }

            return new Vector2(width, height);
        }