Why does the split rule not work correctly on blocks resulting from street creation tool drawing?

Question

Hello everyone. Why does the split rule not work properly on graph block, while the split operation works properly on block that I created through the drawing tool , While the rule is the same. In the first image, the rule is executed on the block resulting from the street creation tool, and the areas of the divided parts are different, while in the second image, the block resulting from the drawing tool is divided into equal parts. Does anyone know the reason for this? very thanks

nicolaisteino · Accepted Answer

My guess is, that you drew the manual rectangle using the rectangle tool (not the polygonal shape tool), resulting in a perfect rectangle, while the lot which was generated from the block is slightly irregular due to imperfections in the way you drew the streets (as there is no tool to draw four streets as a perfect rectangle, only snapping).

If the block is ever so slightly narrower at one end than at the other (meaning that the long sides are not perfectly parallel), the alignScopeToGeometry() operation can only make the scope parallel to one of the long sides. Thus, splitting along the short axis will produce a split, which is parallel only to one of the long sides.

Once you start splitting along the other axis, this would produce identically sized lots on one side, and lots of slightly increasing sizes along the other. This is consistent with your print: You have 13 lots along either long side, and 11 lots of identical size (1760.04…), while all other lot sizes differ. This suggests that the corner lots are slightly skewed (from short ends not being exactly perpendicular to the scope).

You may check if my hunch is correct by using the measure tool to measure the diagonals and/or the edges of the lot generated from the street graphs.

Best, Nic