shell - two different surfaces

Here is San Lorenzo church at Turin built by Guarino Guarini. What I found interesting here is the fact that this plan shows two completely different surfaces. It is like a shell where the interior with the sculpture and the ornaments makes difficult for the visitor to "read" the space and its geometry in contrast to the outside surface where everything seems more clear. So I took a part of this plan in order to experiment and see what will happen if I multiple, rotate or scale it.