fitgeotrans() which Points to use as movingPoints and fixedPoints

I have thought so long about it, that I can not think clear anymore.

Essentially, I have a tilted plane and slightly above this I have a non tilted plane. On these planes images are formed. Additionally, I have rays which aim to the edges of the tilted plane and intersect with the non tilted plane. Now I have the edge poitns of the tilted and the non tilted plane and the intersection points, whcih are all in 2D.

I want to apply tform=fitgeotrans(movingPoints, fixedPoints, 'projective') to get the transformation matrix.At the moment I use as fixedPoints the intersection Points and as movingPoints the edge points of the tilted plane, but is this correct? Or should I use the edge points of both planes?

A clarifying answer is deeply appreciated.