Playing Lego With Python - Rotating Bricks During The Build

Whilst brick rotation is relatively straight forwards (by modifying the rotation matrix for each brick in the ldr file) tracking the corresponding rotation in my build matrix (which tracks brick dimensions and stud availability of bricks in the pile) is complex.  As you rotate the brick you have to rotate and reshape the brick matrix by the same amount.

Although the Lego piles were increasingly "correct", that is to say that any new bricks sat on top an existing stud if one was available in its proposed position there were still occasional problems in the build matrix.  I realised the problems seemed to limited to specific bricks (mainly "odd" flavour bricks like 1x2 and 2x3 bricks and plates) - the placement of these "odd" bricks is trickier as the origin point of the bricks in ldr brick placement does not place "odd" bricks on a stud by default, so they immediately need moving to sit on a stud.  This initial move and any subsequent move needs to be tracked in the build matrix and then also tracked when these bricks were rotated.

Consequently I've had to learn a lot about matrix manipulation!