Screenpoint to point on plane.

//  NPSF3000 - NPSF3001 randomgarbage gmail
//  Free for personal/educational use - all risk is assumed by user.
//  Attribution is nice :P


    Vector3 GetMousePointInWorld_ZAxis()
    {
        //  This is quite simple:

        //  1) Get a ray from the mouse,
        Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);

        //  2) Intersect with a 'plane' (i.e find out where my mouse ray is when it intersects the z axis as defined by our object),
        Plane plane = new Plane(new Vector3(0, 0, 1), transform.position);
        float distance;
        plane.Raycast(ray, out distance);

        //  3)  Return the point.
        return ray.GetPoint(distance);

    }