Alternatively, we can split the 3D array into three 2D arrays, one for each colour channel. Note, this is different from above where we kept the entries as RGB vectors, where just two entries were 0.

[Ben Bartlett] recently got engaged, and the proposal had a unique bit of help in the form of a 3D-printed hexagonal mirror array, whose mirrors are angled just right to spell out a message with th… ...