//3x3 matrix becomes 4x4 like this:-
[ a11 a12 a13 0 ]
[ a21 a22 a23 0 ]
[ a31 a32 a33 0 ]
[ 0 0 0 1 ]
>>> matrix = [
... [1, 2, 3, 4],
... [5, 6, 7, 8],
... [9, 10, 11, 12],
... ]
//3x3 matrix becomes 4x4 like this:-
[ a11 a12 a13 0 ]
[ a21 a22 a23 0 ]
[ a31 a32 a33 0 ]
[ 0 0 0 1 ]
>>> matrix = [
... [1, 2, 3, 4],
... [5, 6, 7, 8],
... [9, 10, 11, 12],
... ]
//3x3 matrix becomes 4x4 like this:-
[ a11 a12 a13 0 ]
[ a21 a22 a23 0 ]
[ a31 a32 a33 0 ]
[ 0 0 0 1 ]
>>> matrix = [
... [1, 2, 3, 4],
... [5, 6, 7, 8],
... [9, 10, 11, 12],
... ]