Map2STL

Find my other Apps, eBooks and an AppleTV app at https://www.pharmpk.com/MyeBooks.html
Privacy Policy Link

Map2STL

is a Topographic Data to 3D Printer File Converter. It is a macOS app I wrote, with a little help from Claude, to solve a problem. I had been able to create STL files for 3D printing of small area of the Earth using a free website. It was fun to see these geographic areas reproduced as solid shapes. While writing this application, after downloading latitude/longitude/altitude data for these areas, I have a better appreciation of why the website stopped working. During development I've found that rate limits on downloading data can make producing higher resolution models more challenging.

v1.2.1 Submitted 12 Jul 2026. Approved 13 Jul 2026

Bug Fix: Too many zero results from USGS server retrieving a 99x99 grid
Requested latitude and longitude precision reduced to 6 decimal places for both USGS and Open-Meteo requests
Added a clean-up step after all points retrieved. Revisited points returning 0.0 and repeat requesting for these points

v1.2 Submitted 9 Jul 2026. Approved

Added the ability to edit elevation data for grid point closest to feature
Data retrieved from data sources is of limited resolution, ~30m to ~90m. Elevation data retrieved maybe an average for a particular grid. In the case of steep changes in elevation this might mean missing a know peak. The ability to edit the elevation of a few important features can result in an improved 3D printed object.
Added the ability to automatically repeat retrieval of a data point reported as zero.
Occasionally, the data server will return an elevation value of zero. Maybe over water, maybe just because. The app will now try one more time to get a non-zero value. These zero values can be seen on the 3D Elevation View if you look below the image. These data points can be fixed by carefully editing the Standard CSV file in a text editor. The USGS data source can be queried manually by sending a URL request to the data source.
https://epqs.nationalmap.gov/v1/json?x=grid latitude value&y=grid longitude value&units=Meters&includeDate=false
The return value should be the elevation

v1.1 Submitted 7 Jul 2026. Approved 8 Jul 2026

Added ability to select area by center and width
Added export in USDZ file format
Added import standard CSV file data previously saved

v1.0 Submitted 2 July 2026. Approved 7 July 2026

Data Sources

1. Open-Meteo

Elevation data by Open-Meteo.com Global, free, no API Key, Rate limited to 600 requests/minute, 5,000 requests per hour and 10,000 requests per day.

2. United States Geological Survey - Elevation Point Query Service National Maps

U.S. only, recommended for U.S., free, no API Key, high quality

3. Simulated Data Useful for learning the app

Citation & Acknowledgement

Open-Meteo and Copernicus DEM

United States Geological Survey - Elevation Point Query Service National Maps

USGS vs Open-Meteo comparison

	Open-Meteo	USGS EPQS
Coverage	Global	US only
Resolution	~90 m (SRTM3) global ~30 m U.S.	~10 m (3DEP)
Rate limit	600 requests/min (free tier) 5,000 requests/hr	No documented rate limit Avoid DOS with some delay
Best for	Quick global overview	High-detail US terrain

Rate Limiting Notes

Open-Meteo

25x25 = 625 points so one model at a time should be OK but no more than 8 models per hour.
49x49 = 2,304 points one model at a time and no more than 2 models per hour
69x69 = 4,900 points maximum is 1 per hour, minimum time about 8-10 minutes

USGS

Requesting 25 points per batch with 2 sec per batch to avoid DOS issues. Slow but steady.

Recommended Approach

Start with Simulated Data and then USGS to generate real data unless you want data outside the US, then use Open-Meteo.

For U.S. data use USGS low resolution to explore the area. For final model use higher resolution but it will take time. Maybe limit to one or two per day. The 3D printer isn't going to be much faster.

Sharp Terrain - Pointy Peaks

With limited resolution, i.e. 30 or 90 m, setting a grid to capture a peak can be a challenge. With one main peak in the area of interest it might be best to the use the 'Enter Coordinates' option. Use the lat/lon of the main peak as the center. This should work BUT, the altitude returned is probably an average for the grid square/rectangle around the peak. You might export the standard csv file, search for the peak lat/lon and replace the value with the known elevation for the main peak. You can then import the edited csv file and generate the STL/USDZ file.

With multiple peaks of interest you might try finding the closest lat/lon for each peak and replacing the returned elevation value with the known height.

Basic Process for Converting Topographical Data to a 3D Image

Opening View Top-Left: Map2STL App Title Top-Center: Map Type Selection Top-Right: Settings and Reset Buttons Middle-Right" Zoom in/out Buttons Bottom-Center: Select Area or Enter Coordinates. Load CSV data if available
Settings View Select Data Source Open Meteo: Global USGS EPQS: U.S. Only Simulated: Not real data Resolution - Number of Grid Points Lower Grid Size is Faster for exploring
Select Area Instructions Drag to draw a Rectangle Option-Drag to draw a Square
Enter Coordinates View Center Latitude and Longitude Size in Km. Note min width Selector for Square (default) Probably need to adjusts dimensions with 3D Printer software for non-square shapes
View Elevation Data Map Zooms to Square/Rectangle Red Dot marks the Center Mount Blue Sky Press View Elevation Data Button or Reset or Load CSV data
Elevation Data View 1 Description of Data Used Region Selected Information Report on suitability of Election Variation 3D Elevation Preview Check below for spikes could be bad data
Elevation Data View 2 STL and USDZ Settings: Base Thickness: 2.0 mm good default Max Height: 50 mm (~2") Vertical Exaggeration: 1x good default Maybe better adjusted with 3D printer software Save CSV Standard CSV: Useful for saving or editing Grid CSV: Could be used by 3D display software for visualization Generate & Save STL file Generate and Save USDZ File both to ~/Downloads Folder

Editing Elevation Data to Better Represent Geographic Features

After Loading a CSV File Ask to Edit the Elevation Data just Loaded Yes to Edit
Edit Peak Elevation 1 Enter the most accurate latitude and longitude available Press 'Find the Nearest Grid Point' Press 'Done'
Edit Peak Elevation 2 Nearest Grid Point Displayed Enter the Best Estimate for the Elevation Press 'Apply Correction'
Edit Another Peak? Yes, for another feature No, to continue>
Elevation Data with Corrected Value(s) Review 3D View for errant peaks
A 3D Printed Example - Mt Rainier