SandTableGeography

A way to convert topographic maps into gcode for a kinetic sand table. This takes input data as .tif or .hgt files and creates a single continuous path in gcode that traces to topography lines. The given geographic bounding box can be rotated in increments of 90 degrees and will be cropped to fit the exact dimentions of the specified table.

Visual

North is to the left

Requirements

Tested with python version 3.9.0

Install dependencies

pip install -r ./requirements.txt

Inputs

Positionals

Argument	Type	Example
Latitude 1	Float	44.04207
Longitude 1	Float	-71.85694
Latitude 2	Float	43.99183
Longitude 2	Float	-71.80904
Table Dimention	WIDTHxHEIGHT or DIAMETER in millimeters	880x550

Optionals

Short	Long	Type	Default	Description
-t	--topography	file or directory path	./input_data/	The elevation data to read in
-o	--output	file path	output.gcode	The output gcode file. The image representation will use the same name, with a .png extension
-r	--rotation	integer (0,90,180,270)	0	The rotation of the map in degrees counter clockwise
-n	--num-contours	integer	30	The number of elevation contours to draw betwween the minimum and maximum points of elevation of the mapped area
-d	--debug-dir	directory path	None	A directory to output debugging related files. This includes a drawing of each elevation, before and after loops have been merged. This may generate a lot of image files and is off by default

Example: Mt. Moosilauke

python3 ./main.py 44.04207 -71.85694 44.000153 -71.80904 880x550 -r 90

Expected Output

• ./output.gcode The gcode output for the table
• ./output.png An image showing the path the gcode will take on the table

Output image

North is to the left

The path starts at the yellow end and moves toward the red end.

Limitations

• Patterns can only be rotated in increments of 90 degrees
• Water features are not handled
• Does not handle concave topography features

Testing

Run unit tests

python3 -m pytest testing/