Documentation

🗺️ Overview

3D Topo Generator is a web application for creating 3D printable terrain models from digital elevation data. Select any area on Earth, configure your model, and choose the processing workflow that best fits your project. You can also upload GPX, KML, or GeoJSON tracks, visualize recorded activities, associate them with manually drawn bounding boxes, and turn selected routes and pins into physical details on supported exports.

When to use professional GIS/CAD tools instead

If you need very large geospatial pipelines, advanced GIS analysis, or highly custom production modeling, tools like ArcGIS/QGIS/Blender remain better suited. 3D Topo Generator is optimized for fast terrain-to-print workflows with minimal setup.

🖥️ Browser vs ☁️ Cloud: Two Workflows, One Simple Choice

3D Topo Generator offers two purpose-built ways to create terrain. Browser mode turns your device into an interactive creative workshop with the richest export toolkit. Cloud mode moves terrain computation away from your device, applies no fixed app-defined geographic-area ceiling, and delivers the result asynchronously through Cloud Jobs. This ability to generate terrain far beyond normal browser CPU and memory limits is Cloud Processing's defining advantage. One shared credit balance supports both workflows.

Swipe horizontally to explore the full comparison.

Why the Processing Cores Are Kept Separate

The two modes solve different engineering problems, so they intentionally follow separate execution paths.

Keeping the cores separate lets each mode evolve around its real strengths. It also prevents a browser-only feature from being silently ignored by a paid Cloud job: unsupported combinations are clearly blocked before credits are charged. The result is a transparent choice today and a safe foundation for future Cloud capabilities.

⚡ Performance & Processing

Terrain generation can be demanding, especially when a large geographic area produces a dense elevation grid. Use these practical guidelines to balance detail, processing time, and device resources. If you have not chosen a workflow yet, start with the Browser vs Cloud comparison.

Relative Area Workload Guide

Area Size	Typical Browser Workload	Recommendation
< 25 km²	Light	Usually a comfortable Browser starting point
25-100 km²	Moderate	Generally suitable for Browser mode on a modern device
100-200 km²	Heavy and device-dependent	Browser remains available; consider stronger reduction or Cloud mode
> 200 km²	Very heavy and device-dependent	Cloud is usually the safer choice; Browser is not artificially blocked

These bands describe relative workload rather than guaranteed completion times. DEM resolution and coverage, reduction factor, smoothing, map elements, network speed, available memory, CPU, and browser limits can make two boxes with the same area behave very differently.

What Happens During Browser Generation

Shared Credits and Two Clear Prices

The balance in the top account area, below the processing-mode switch, is shared by Browser exports and Cloud jobs. Buying a pack adds credits once; you then decide which workflow should spend them.

Compare both options at a glance. The app always shows the exact credit price before a purchase or job submission.

🌐 Browser Support

For the best experience, use an up-to-date version of one of the browsers listed below. The app uses modern browser features for file handling, local processing, storage, and 3D graphics. The size and complexity of the terrain models you can process also depend on your device's memory and performance.

• Google Chrome or Microsoft Edge
• Mozilla Firefox
• Safari on macOS or iOS
• Google Chrome on Android

🧭 Welcome Guide & Workspace

Welcome Guide

When you first access the main application, a welcome modal appears with the 4 core steps to get started:

1. Get Your API Key: Configure your OpenTopography API key via the user menu
2. Select Your Area: Navigate the map or upload a GPX, KML, or GeoJSON route to locate your activity
3. Create a Bounding Box: Select 4 points on the map or enter exact limits
4. Generate & Download: Customize settings and create your 3D model

You can close this modal anytime and optionally hide it for the current session.

Understanding the Workspace Layout

The workspace is organized for quick terrain selection and fast iteration:

Desktop Layout

• Left Side (65%): Interactive map with one compact floating toolbar. Icons, a divider, and short Draw Box / Set Box / Pin / Track labels distinguish the blue box tools from the magenta/purple/indigo element tools; full names remain available as tooltips
• Right Side (35%): Control panel with integrated user menu, a compact portable-project import callout, and one space-saving Map Elements card with Boxes, Tracks, and Pins tabs

Mobile Layout

• Top: Fixed header with panel toggle button and user avatar menu
• Main Area: Full-height interactive map optimized for touch navigation and search-first location workflow
• Panel Quick Actions: matched controls for drawing or precisely entering a box, followed by pin placement and GPS-track upload
• Collapsible Panel: Tap ☰ Panel to open the full controls sheet, switch the Map Elements tab you need, and use ✕ Close Panel to return to map focus

Map Elements Tabs

The single Map Elements card replaces three long simultaneous lists. It always opens on Boxes, with Tracks second and Pins third. Selecting a tab reveals only that list; nothing is deleted or disabled when another tab is active. Count badges update as elements are added or removed. Keyboard users can move between tabs with Left/Right arrows and jump with Home or End.

When a list is empty, the panel remains useful instead of appearing blank. A colour-matched guidance card identifies the next action: Draw Bounding Box or Set Bounding Box for Boxes, Upload Track for GPX/KML/GeoJSON routes, and Place Pin for landmarks. The guidance disappears when the first item is added and returns automatically if the last item is removed.

Bounding Box Buttons (What They Do)

• Draw Box: starts four-point area selection on the map. Its full tooltip is Draw Bounding Box.
• Set Box: opens the precise south/west/north/east entry form beside the drawing action. Its full tooltip is Set Bounding Box.
• ▶ / ▼ (Collapse): hides or expands one box details panel to keep the list clean.
• 🔍 Zoom to box: centers and fits the map on that bounding box.
• Edit / Finish Edit: enables corner-handle editing for quick shape adjustments.
• Rename: changes the box title for better project organization.
• Hide / Show: toggles box visibility on the map without deleting it.
• Delete: permanently removes the selected bounding box.

Pin Buttons (What They Do)

• Pin: enters pin-placement mode from the unified map toolbar; choose the Pins tab to manage the resulting list.
• 👁️ All: toggles visibility for all pins at once.
• 🔍 (Pin list): zooms directly to the selected pin position.
• ✏️ (Pin list): edits pin tag, color, and size.
• 👁️ / 👁️‍🗨️ (Pin list): shows or hides an individual pin.
• 🗑️ (Pin list): deletes the selected pin.

GPS Track Controls (What They Do)

• Track: beside Pin in the unified map toolbar, imports one or more GPX, KML, or GeoJSON line files and immediately draws their routes. Choose the Tracks tab for the resulting route list and controls.
• ⌖: fits the map to the complete selected track.
• ◉ / ◌: shows or hides the route without deleting its stored data or box association.
• ✎: renames the imported track.
• ✕: deletes the track from the map and local IndexedDB storage.
• Activity: classifies the route as trekking/hiking, running, cycling, cruising/sailing, skiing, or other.
• Map/print color: sets the Leaflet line color and records the intended print color for the track.
• Track width / Raised height: controls the physical millimetre dimensions of the printable route.

〰 GPS Tracks & Printable Routes

The GPS Tracks workflow turns a recorded surface activity into both a map guide and a physical feature on the terrain model. It is designed for trekking, hiking, running, cycling, cruising, sailing, skiing, and similar activities recorded on land or sea.

Supported Track Formats and Content

• GPX: GPX 1.0/1.1 .gpx files using trk → trkseg → trkpt or rte → rtept, including multiple segments.
• KML: .kml files using LineString geometry in placemarks, documents, folders, or MultiGeometry, plus Google Earth gx:Track.
• GeoJSON: .geojson and GeoJSON .json files using LineString or MultiLineString directly or inside Features, FeatureCollections, and GeometryCollections.
• Coordinates: WGS84 longitude/latitude is normalized to the application's latitude/longitude model. Optional GPX/KML elevation and GPX or KML gx:Track timestamps are preserved when available.
• Ignored geometry: KML points and GeoJSON Point, MultiPoint, Polygon, and MultiPolygon objects are intentionally ignored. Add points of interest with the dedicated pin controls.
• Safety limits: maximum 10 MB and 100,000 usable line points per imported file, regardless of format.

How Bounding-Box Association Works

Uploading a track file does not create or change a bounding box. After the track is visible, draw or edit boxes using the normal manual workflow. Every box then displays a GPS tracks in this box panel:

• Complete: every point of the route is inside the box.
• Partial: only part of the route is inside, or a segment crosses the box boundary.
• Not listed: the route does not intersect the box.
• Checkbox: determines whether that route is included in this particular model. One uploaded track can therefore be used differently across multiple boxes.

How the Printable Track Is Built

1. The selected route is clipped to the box before geometry generation.
2. Latitude/longitude points are transformed into the model's X/Y coordinate system.
3. The centreline receives shape-preserving corner smoothing and adaptive station spacing, while keeping the recorded segment endpoints.
4. Each station uses a seven-point cross-section: a rounded crown makes the route clear and attractive, while bevelled shoulders blend it cleanly into the model.
5. Every point across the route width is projected onto the exact triangulated terrain surface. This is more accurate on side slopes than sampling only the centreline.
6. The underside follows the terrain and is embedded by a controlled amount. For an open route, the top, underside, sides, and two end caps form one closed, watertight solid.
7. If a circular imported route repeats its starting coordinate at the end, the duplicate terminal station is removed and the last sweep section joins directly to the first. No coincident end caps are generated, preventing four-face non-manifold edges at the loop closure.
8. Dense recordings use bounded simplification and resampling to control browser memory, generation time, and output size without unnecessarily changing the visible route.

Preview Visualization & Terrain Analysis

The preview always opens with the Generated model and its selected colour. The Visualization panel then offers three optional, non-destructive ways to inspect or present the same mesh. Changing these controls never alters the STL or 3MF; it only changes the interactive view and the image produced by Save image.

If the box contains tracks or pins, their exact printable geometry is prepared in the background and added to the centre-anchored model without delaying the terrain preview. Map elements presents separate GPS Tracks and Pins groups, retaining each track's imported name and each pin's tag. Every item has its own checkbox and preview colour, so multiple elements can be shown, hidden, and styled independently. Choose Original to restore that item's configured map colour and update its colour picker to the restored value. The current combination appears in Save image. These controls are presentation-only: they do not change which elements are included in a download and do not recolour STL or 3MF parts.

Generated model — default view

This is the model-focused view shown when the preview opens. It displays the generated terrain with its selected model colour and can include independently styled tracks and pins.

Classic hillshade

Classic hillshade starts with traditional neutral grey, northwest light at 315°, and 45° light altitude. Change the relief colour, intensity, compass direction, and altitude to reveal different terrain structures.

Slope heatmap

The slope heatmap displays real geographic slope calculated from the smoothed DEM before vertical exaggeration. Green represents 0–15° flat or gentle ground, yellow represents 15–30° moderate slopes, and red represents terrain steeper than 30°. Two independent controls prevent different provenance categories from being confused with flat terrain. Mask source NoData displays genuinely missing and subsequently interpolated cells in neutral grey. Mask classified sea displays boundary-classified flat sea in neutral blue-grey; it is available only when Repair missing sea feature around coastlines produced a sea mask during generation. Disable either control to inspect that category's calculated slope colour. Both controls change only the slope preview—not the terrain mesh, other visualization styles, STL, or 3MF.

Contours & topographic colour

This style draws smooth procedural contour lines from real elevation values. Automatic spacing aims for roughly fifteen readable levels and rounds to familiar cartographic intervals; disable it to enter a manual interval in metres.

Choose among nine colour scales: Classic Topographic, Printed Atlas, Alpine Relief, Forest & Highlands, Desert Relief, Classic Bathymetry, Deep Ocean, Coast & Land, and Ocean-to-Summit. The final two are hybrid scales permanently anchored to actual zero metres: elevations at or below 0 m—including models that are entirely underwater—use only the blue bathymetric half, while elevations above 0 m and entirely terrestrial models use only the land half. The colour ramp remains clean and uninterrupted without an overlaid coastline marker.

Land, Coast, and Sea Activities

The route always follows the surface represented by the selected DEM. Standard land DEMs may represent the sea as a flat zero-elevation surface. For cruises, sailing routes, coastal relief, or seabed models, choose SRTM15Plus, GEBCOIceTopo, or GEBCOSubIceTopo when their bathymetric representation matches your project.

Track Storage and Data Flow

Imported tracks are stored locally in browser IndexedDB so they survive reloads without filling localStorage. GPX, KML, and GeoJSON routes remain part of the Browser workflow because printable tracks are not currently a Cloud feature. Deleting a track from the Tracks tab removes its local stored record.

📖 Usage Guide

Follow this sequence from registration to model generation:

Step 1: Create Your Account

1. Click the "Launch App" button from the landing page or navigation bar.
2. If you're not logged in, you'll be redirected to authentication.
3. Register with name, email, and password.
4. After login, your user menu appears with your initials/avatar.

Step 2: Get Your OpenTopography API Key

1. Visit OpenTopography API Registration.
2. Request your API key and copy it.

Step 3: Configure API Key in the App

From Landing Page

1. Open your user menu in the top navigation.
2. Click OT API Key.
3. You will be redirected to the app with the settings modal opened.

From Main Application

1. Desktop: open the integrated menu in the right panel and click OT API Key.
2. Mobile: tap user avatar in the top header and choose OT API Key.

Save the Key

1. Paste API key in the input field.
2. Click Save API Key (or press Enter).
3. Confirm status message shows the key is configured.

Step 4: Optional Track Upload, Manual Bounding Box, and Pins

Optional: Upload a GPS Track First

1. Choose Track beside Pin in the desktop map toolbar (or Upload GPS Track on mobile) and select one or more GPX, KML, .geojson, or GeoJSON .json files.
2. Confirm the track appears on the map; the map automatically fits the imported route. Open the Tracks tab in Map Elements to manage it.
3. Use the track controls to rename it, choose an activity, set its color, and configure printable width and raised height.
4. Use show/hide and zoom controls to inspect the route before framing the terrain.

Select the Box Area

1. Choose Draw Box on desktop (or Draw New Bounding Box on mobile) and place 4 points on the map.
2. For repeatable limits, choose Set Box on desktop (or Set Bounding Box on mobile) and enter south, west, north, and east directly. The optional name starts empty; Add box assigns the next automatic Box number when no name is entered.
3. To reconstruct a saved configuration, choose Import project and select the JSON downloaded from an earlier preview.
4. Use the search tool—or the uploaded track itself—to position the map before drawing.
5. Review the resulting area value in the box details.
6. Review GPS tracks in this box. A route is labeled Complete or Partial; use its checkbox to include or exclude it from this box.

Optional: Add Pins

1. Choose Pin on desktop (or Place Pin on mobile) and tap the map to add landmarks, then open the Pins tab to manage them.
2. Set pin tag, color, and size.
3. Use pin list actions to zoom, edit, hide/show, or delete.
4. Keep pins inside the selected box if you want pin-inclusive exports in Browser mode.

Step 5: Configure Bounding Box Parameters (Detailed)

After creating or selecting a box, configure the model parameters in the box panel. These values control the final physical print size, terrain readability, and processing performance:

• Width (mm) / Length (mm): define the real-world print footprint of the generated model for this specific box.
• Dimensions Link: keeps width/length proportional to the map area ratio, so changing one value updates the other automatically.
• Vertical Exaggeration: scales elevation differences along Z. Higher values emphasize relief and cliffs; lower values keep a more realistic vertical profile.
• Smoothness: applies terrain smoothing before mesh generation. Increase it to reduce noise and sharp micro-artefacts; keep it lower for more raw terrain detail.
• DEM Source: selects which elevation dataset is queried. Coverage, accuracy, and resolution vary by region and source.
• Repair missing sea feature around coastlines (Browser only): use it for coastal models when the selected land DEM leaves sea areas empty (NoData) or represents them as flat 0 m regions. It restores boundary-connected missing-data regions or 0 m areas to sea level while preserving underwater elevation data. Enclosed NoData gaps are interpolated, enclosed zero plateaus remain terrain, and legitimate negative elevations are not treated as missing. Leave it disabled for inland models, genuine land close to 0 m, or whenever an edge gap could represent incomplete coverage rather than water. SRTM15Plus and both GEBCO sources preserve their measured bathymetric zero and negative values. The setting is off by default, disabled in Cloud mode, and not included in Cloud job requests.
• Resolution Reduction Factor: downsamples input elevation points before mesh creation. Higher reduction is faster/lighter but can remove fine detail.
• Composition Mode: chooses model strategy:
  • Full-Solid: single terrain body.
  • Topographic: segmented terrain bands for multi-part or multi-color workflows.
• Topographic settings (visible only when Topographic mode is selected): configure how elevation is split into geometry bands. This includes:
  • Band Mode: choose how the terrain is partitioned:
    • Adaptive: balances band distribution based on terrain elevation distribution; usually best for irregular landscapes.
    • Equal Step: splits vertical range into equal-height bands; useful for clean, contour-like layering.
    • Coastal Preserve: keeps the complete low-elevation/coastal range together in the first topography level, then divides the remaining higher relief across the other levels without leaving a vertical gap.
  • Topography Bands: number of generated terrain bands (in addition to the base).
  • Coastal Preserve Strength % (conditional): shown only when Band Mode = Coastal Preserve. A low value behaves closer to Adaptive mode. A high value groups a wider coastal elevation range into topography level 1. The base remains a continuous 4 mm solid, and every topography level starts exactly where the previous level ends.
  • Note: topographic mode currently focuses on geometry banding and no longer uses color scheme selection in this panel.
• Cloud Processing Cost (Cloud mode): shows required credits for that specific box before submission.
• GPS tracks in this box: lists every intersecting route, shows Complete/Partial status, and stores per-box inclusion choices.

Step 6: Choose Processing Mode

Use the Browser · Local / Cloud · Remote switch below the menu area for a quick change, or open Processing Mode for the complete comparison, shared balance, and credit packs. Both controls remain synchronized. See the complete Browser vs Cloud capability table whenever you want a quick recommendation:

• Interactive creation and advanced exports: prefer Browser Processing whenever the selected area and DEM are comfortable for your device.
• Models with printable GPS tracks: use Browser Processing, regardless of area, because track geometry is currently generated locally.
• Boxes above 100 km²: the Browser warning is advisory. Local generation may still work; consider a stronger reduction factor and allow more time.
• Projects beyond your device's practical CPU or memory limits: prefer Cloud Processing, which has no fixed app-defined area ceiling.

Step 7: Generate

1. Check box settings and selected mode.
2. Click Generate 3D Model.
3. Follow progress until completion.
4. Use the large interactive preview to rotate freely in every direction—including roll and underside inspection—and zoom until the terrain is framed the way you want. Rotation and zoom remain anchored to the model's exact three-dimensional centre, while the camera composition places the terrain slightly higher in the stage to provide more useful space during close inspection. Panning is intentionally disabled. Choose Reset view at any time to return to the fitted, raised starting camera, or Save image to download the current view as a high-resolution PNG. The image is created entirely in your browser and is separate from the printable model files.
5. The header identifies the terrain and source file and keeps Save project JSON beside the visually distinct Unlock downloads action. Saving the JSON is free and preserves exact bounds, settings, printable routes, pins, and fingerprint for later import.
6. Map elements and Model summary both start collapsed so optional presentation controls and technical details do not compete with the model. Expand Map elements to show, hide, recolour, or restore the Original preview colour of individual tracks and pins. Expand Model summary for the DEM, boundary-sea diagnostics, map-element counts, physical dimensions, elevation range, and triangle statistics.
7. The app checks whether this exact configuration already has a Browser Export Pass. If not, review the displayed area and credit price, then choose Unlock downloads. The authenticated service transiently verifies the complete canonical configuration—including selected printable tracks and pins—recalculates its fingerprint and price, and stores only the entitlement summary rather than the complete geometry. One server transaction charges once; all applicable STL, 3MF, and guide buttons then enable. Regenerating or retrying the identical project does not charge again.
8. Choose STL (Terrain Only) or STL + Tracks/Pins. Browser exports normally pass strict edge, orientation, volume, manifold, and Boolean-union checks before download. If arbitrary map geometry cannot be normalized universally, a quiet compatibility export preserves all shells for slicer-side repair instead of blocking the file.
9. In Topographic mode, choose Segmented 3MF + Map Elements to keep the base, watertight elevation bands, tracks, and pins as separate aligned objects.

🧭 Printing Tips & Model Orientation

The usual and most stable setup is to place the model with its broad flat base directly on the build plate. This maximizes adhesion, minimizes supports, and is the best starting point for most terrain prints. However, when horizontal layer stepping is highly visible across slopes or fine relief, an edge-on vertical orientation can produce a cleaner-looking terrain face because the layer direction crosses the model differently.

🔄 End-to-End Processing Flows

Once you have selected a mode, follow its operational sequence below. For feature availability and the reasoning behind each workflow, use the capability comparison.

Browser Processing Flow

1. Activate Browser Processing in Processing Mode.
2. Optionally upload GPX, KML, or GeoJSON tracks, then manually draw a box and select the Complete/Partial tracks to include.
3. Generate locally in your browser (Web Worker path).
4. After completion, inspect and save PNG/project JSON for free. Then reuse an existing entitlement or unlock one Browser Export Pass for the exact configuration.
5. With the pass unlocked, export:
   • STL terrain only
   • STL + selected GPS tracks + pins as one printable file
   • Watertight segmented 3MF terrain
   • Segmented 3MF + Map Elements, with tracks and pins as separate aligned objects
   • Printing guide TXT

Cloud Processing Flow

1. Switch to Cloud Processing.
2. Confirm the shared balance has enough credits; buy a pack only when needed (PayPal account or guest checkout, no PayPal registration required).
3. Review Cloud Processing Cost for the selected box.
4. Generate to submit async cloud job.
5. Monitor job in Cloud Jobs and download STL when status is Completed.

🖨️ Get 3D Printing Cost Estimates

After downloading your STL, you can estimate print costs using the free Print-Calculator tool. For models generated by this service, there is currently a required preparation step before the estimate is accurate.

1. Open Print-Calculator.
2. Import the generated model into your slicer software.
3. Export the model from the slicer in a Print-Calculator compatible format (STL/OBJ/3DS).
4. Upload that exported file in Print-Calculator, then enter model/material parameters.
5. Review instant estimate and request a personalized quote if needed.

🌍 DEM Data Sources

The application supports multiple Digital Elevation Model sources, each with different coverage and resolution. Below you'll find detailed information about each DEM family:

SRTM Family (Shuttle Radar Topography Mission)

An SRTM DEM is a Digital Elevation Model created from data collected by NASA's Shuttle Radar Topography Mission (SRTM) in 2000. It provides near-global elevation data for most of the world at resolutions of 3 arc-seconds (~90m) and 1 arc-second (~30m), filling gaps in elevation data to provide a continuous topographic surface. To be noted that SRTM15PLUS integrates the original Shuttle Radar Topography Mission (SRTM) land data with improved ocean bathymetry, which is derived from a combination of direct shipboard measurements and predicted depths using satellite altimetry.

• SRTMGL3: SRTM GL3 90m resolution
• SRTMGL1: SRTM GL1 30m resolution
• SRTMGL1_E: SRTM GL1 Ellipsoidal 30m resolution
• SRTM15Plus: Global Bathymetry SRTM15+ V2.1 500m resolution

ALOS World 3D (AW3D30)

AW3D30 is a global digital surface model (DSM) with a 30-meter (1 arcsec) horizontal resolution, generated from satellite stereo images by JAXA (Japan Aerospace Exploration Agency).

• AW3D30: ALOS World 3D 30m resolution
• AW3D30_E: ALOS World 3D Ellipsoidal 30m resolution

NASADEM

NASADEM (NASA Making Earth System Data Records for Use in Research Environments) is a digital elevation model (DEM) that provides global, near-global land elevation data at a resolution of 1 arc second (approximately 30 meters). It is a modernization of the original Shuttle Radar Topography Mission (SRTM) DEM, using improved processing techniques.

• NASADEM: NASADEM Global DEM at approximately 30m resolution

Copernicus DEM

The Copernicus DEM is a Digital Surface Model (DSM) that represents the Earth's surface, including buildings, vegetation, and other infrastructure, in a 30-meter or 90-meter resolution format.

• COP30: Copernicus Global DSM 30m resolution
• COP90: Copernicus Global DSM 90m resolution

European Digital Terrain Model (EU_DTM)

The European Digital Terrain Model (EU_DTM) is a 30-meter resolution model representing the bare-earth surface of Continental Europe, developed by Dr. Tom Hengl and the OpenGeoHub Foundation, using an Ensemble Machine Learning (EML) algorithm trained on various Digital Elevation Models (DEMs) and elevation data from GEDI and ICESat-2. Unlike the older EU-DEM, which was a Digital Surface Model and is no longer maintained, the EU_DTM specifically models the ground's terrain by removing vegetation and buildings, making it suitable for analyses requiring the underlying topography of the landscape.

• EU_DTM: DTM 30m resolution (Continental Europe only)

GEDI (Global Ecosystem Dynamics Investigation)

The Global Ecosystem Dynamics Investigation (GEDI) produces high resolution laser ranging observations of the 3D structure of the Earth. GEDI's precise measurements of forest canopy height, canopy vertical structure, and surface elevation greatly advance the ability to characterize important carbon and water cycling processes, biodiversity, and habitat. GEDI was funded as a NASA Earth Ventures Instrument (EVI) mission. It was launched to the International Space Station in December 2018 and completed initial orbit checkout in April 2019.

• GEDI_L3: DTM 1000m resolution

GEBCO (General Bathymetric Chart of the Oceans)

The GEBCO DEM is a 15 arc-second resolution global elevation model that provides continuous coverage of both ocean depths (bathymetry) and land/ice surface heights (topography), with negative values representing water depths and positive values representing land/ice heights. Developed by the General Bathymetric Chart of the Oceans (GEBCO), it's a composite of diverse data sources, including satellite-derived gravity and ship-track soundings.

• GEBCOIceTopo: Global Bathymetry 500m resolution (includes ice topography)
• GEBCOSubIceTopo: Global Bathymetry 500m resolution (sub-ice topography)

Choosing the Right Source

• For detailed terrain: Use SRTMGL1, NASADEM, COP30, or AW3D30 (30m resolution)
• For larger areas: Use SRTMGL3 or COP90 (90m resolution)
• For coastal areas and bathymetry: SRTM15Plus or GEBCO sources include ocean depth data
• For mountains: NASADEM or COP30 provide excellent detail
• For European terrain: EU_DTM provides bare-earth surface modeling
• For polar regions: GEBCO sources include ice topography data
• For vegetation analysis: GEDI_L3 includes canopy height information

🔧 Troubleshooting

Common issues and their solutions:

API Key Issues

❌ "Invalid API Key" or "Unauthorized" Error

• Verify your API key is correctly copied from OpenTopography (32-character hexadecimal string)
• Check that there are no extra spaces before or after the key
• Ensure your OpenTopography account is active and the API key hasn't expired
• Try generating a new API key from the OpenTopography portal

❌ API Key Not Saving

• Make sure you're logged into the application
• Check that your browser allows local storage/account sync (private/incognito mode may restrict persistence)
• Clear your browser cache and try again

Model Generation Issues

❌ "No Data Available" for Selected Area

• Try a different DEM source - not all sources cover all regions
• For ocean areas, use SRTM15Plus or GEBCO sources
• For European terrain, try EU_DTM
• Verify your bounding box coordinates are correct

❌ Processing Takes Too Long or Freezes

• Reduce the area size if practical, or switch to Cloud mode when the project exceeds your device's comfortable limits; Browser mode has no documented hard maximum
• Increase the Resolution Reduction Factor (e.g., 3 or 4 instead of 2)
• Close other browser tabs to free up memory
• Try using a desktop browser instead of mobile for larger areas

❌ Model Appears Flat

• Increase the Vertical Exaggeration value (try 2x or 3x)
• Check if the selected area actually has elevation variation
• Try a higher resolution DEM source like SRTMGL1 or COP30

❌ Pins Are Missing in the Downloaded File

• Use the purple combined STL + Track(s)/Pin(s) button in the download modal
• Ensure pins are visible and located inside the selected bounding box
• If needed, use the pin list to zoom and verify each pin position before regenerating
• Important: pins in merged STL and segmented 3MF are currently Browser mode export options

❌ A GPS Track File Will Not Import

• Confirm the filename ends in .gpx, .kml, .geojson, or .json and that its content matches that format
• For GPX, include a track segment or route with at least two valid points; for KML, include a LineString or gx:Track; for GeoJSON, include a LineString or MultiLineString
• KML and GeoJSON point geometries are intentionally ignored; create points of interest with the pin system
• The current limits are 10 MB and 100,000 usable line points per file
• Re-export proprietary activity data as GPX 1.1, KML, or GeoJSON if necessary

❌ GPS Track Does Not Appear in a Bounding Box

• Use the track's ⌖ Zoom control and compare its route with the box
• Edit the box corners so at least one route segment intersects the box
• A segment crossing the box is detected even when its original recorded points lie outside
• Check that the route has not been deleted; hiding it affects map display but does not remove association

❌ GPS Track Is Missing in the Downloaded Model

• Use Browser Processing; printable GPS tracks are not currently generated by Cloud jobs
• In the bounding-box card, confirm the track appears as Complete or Partial and its checkbox is selected
• Use the combined STL + Track(s)/Pin(s) button or Segmented 3MF + Map Elements, not the terrain-only button
• Increase Track width or Raised height if the path is present but too fine for the slicer's current nozzle/profile

❌ Segmented 3MF + Map Elements Is Missing

• 3MF exports are available only in Topographic mode
• Ensure at least one selected GPS track or pin intersects the selected bounding box
• Use Segmented 3MF + Map Elements to export terrain bands, tracks, and pins as separate aligned objects
• Important: segmented 3MF exports are currently Browser mode only

❌ Slicer Reports Empty Areas or Open Surfaces in an Old 3MF

• Regenerate the 3MF with the current version; older segmented files used the previous surface-slice implementation
• Current terrain bands are closed manifold solids with sealed contour walls, top surfaces, and bottoms
• Adjacent bands now meet exactly without gaps or artificial overlap
• Confirm that the current file shows parts named base, topo-1, topo-2, and so on; older names indicate an older export

❌ Slicer Asks to Repair an STL or 3MF

• Regenerate the STL with the current Browser version; older combined files could contain individually closed but intersecting shells
• The current exporter repairs face orientation, requires every edge to have exactly two incident faces, validates positive volume, and passes the result through a manifold geometry kernel
• Terrain, GPS routes, and pins are now Boolean-unioned so hidden internal intersection faces are removed
• Circular imported activities are recognized as closed sweeps, so repeated start/end coordinates no longer create overlapping end caps
• Real-world recordings can still contain exact retraces, self-overlaps, or other geometry that cannot be repaired universally. In that exceptional case, the app quietly downloads a part-preserving compatibility file instead of blocking your work; the slicer may then offer its own repair action
• Inspect the slicer's repaired layer preview—especially the route, model underside, and contact with the terrain—before printing. If it looks correct, save the repaired slicer project or re-export the repaired mesh

Browser Export Pass & Project Recovery

❌ Download Buttons Remain Locked

• Wait for the entitlement check to finish and confirm you are signed in.
• Review the required credits shown in the preview; buy a shared credit pack if the balance is insufficient.
• If the unlock request fails, no credit is charged. Retry after connectivity is restored.
• An identical purchased project should unlock automatically. If it does not, import the original JSON rather than manually approximating the box.

❌ Purchased Model Says “Manifest Required”

• The account entitlement still exists, but complete route, pin, and model settings were removed from this browser or purchased on another device.
• Choose Import project and select the JSON saved from the original preview.
• The app recalculates and verifies the fingerprint; a modified/incomplete file is rejected instead of being attached to the wrong purchase.

Download Issues

❌ STL File Won't Download

• Check that pop-up blockers aren't preventing the download
• Try a different browser if the issue persists
• Ensure sufficient disk space is available

Display Issues

❌ Preview Image Won't Save

• Wait until the interactive model has finished loading and the Save image button is enabled
• Allow automatic downloads for the site if the browser blocks the PNG
• The saved image uses the current rotation, zoom, and slightly raised composition; use Reset view before saving if you want the original fitted view

❌ 3D Preview Not Loading

• Ensure WebGL is enabled in your browser
• Update your graphics drivers
• Try disabling hardware acceleration in browser settings
• Use a different browser (Chrome typically has the best WebGL support)

👨‍💻 Credits

Created by Carmelo Sammarco (Sicilian4Ever)

This application represents the intersection of geospatial science and modern web technology. Built with passion for cartography, 3D printing, and open-source software.