A couple people have asked me how I create the drawings of the puzzles that you
see here, such as the one in the frame below. The answer is that I use a free
ray-tracing program called povray and a
few python programs that I wrote myself. I am making these python programs
freely available here. These were written one weekend a few years ago; they
have shortcomings but may still be useful.
Packing a 4x4x4 with 3 F-pentacubes and 2 G-heptacubes
The two python programs I wrote:
Three files related to the example above:
- puzzle.txt
is the simple puzzle description file for the puzzle above.
- puzzle.ini is the ini file for povray.
This file is created from puzzle.txt by solution_to_pov_pieces; I've
included it here so that you can have a way to tell if things are
working.
- puzzle.pov is the pov file for povray.
This file is also created from puzzle.txt by solution_to_pov_pieces.
The python programs run from a command-line shell, such as bash. You will need
to have python installed on your machine. You will also need to install povray.
The puzzle description format is described at the top of solution_to_pov_pieces.
Basically you name the pieces anyway you want and show the name of the piece
occupying each cell. Names are separated by whitespace across a line, and
blank lines separate layers. solution_to_pov_pieces will figure out the shape
of each piece from this, will assign colors to pieces so that neighboring
pieces have different colors, and will also decide what order to draw the
pieces. It is actually not that great at piece ordering, but for small puzzles
it is usually OK (it needs a better heuristic for determining which cells
obscure which other cells). Coloring and piece order can be overridden in the
input file (perhaps someday I will post an example here showing that).
Solution_to_pov_pieces also provides other command-line arguments to get the
drawings to come out right. It has settings for camera distance and camera
translation (≈ position). The defaults are set up for a 4x4x4 puzzle.
For larger puzzles you will need to move the camera farther away. I recommend
the --noclock option initially (so that only the final image will be drawn),
using povray's width=100 height=100, until you get the camera settings right.
Anyway, to convert the puzzle description to a series of images, do this:
./solution_to_pov_pieces.py puzzle.txt
time povray puzzle.ini width=200 height=200
To create the html files that go along with it, do this:
./make_solution_html.py \
"Packing three F-pentacubes and two G-heptacubes into 4x4x4" \
--index="puzzle01.html" \
--solution="puzzle10.html" \
"puzzle%02d.html" \
"puzzle%02d.png" \
10
