View the 3D site model
Build a 3D terrain model of your site from public elevation data, drape map or satellite imagery over it and see every asset in place.
On this page
The 3D view shows your project on real terrain: the ground built from public elevation data, map or satellite imagery draped over it, and your points, lines, routes and 3D scans placed on top. It covers the few square kilometres you're working on, not the whole globe.
Before you start
- An active project.
- A connection the first time, to download the terrain for your area. After that the model is kept on the phone.
Open the 3D view
Any of these switch to 3D:
- On the Survey tab, tap 3D in the 2D / 3D switch.
- In an asset's details, tap View in 3D. The view frames that asset.
- In a 3D scan's viewer, open the ⋯ menu and tap View on the site in 3D.
Build the model the first time
The first time a project is opened in 3D, the app asks which patch of ground to model. Nothing downloads until you choose.
- Tap 3D. The 3D area picker opens. If you close it, the banner at the top left says Choose the 3D area; tap Choose to open it again.
- Pan and zoom the map until the white square covers your site. The square's size is shown above it.
- Or tap a preset below the map:
- 500 m, 1 km, 2 km, 5 km: a square of that size around the current centre.
- Fit assets: the box around everything in the project.
- Built area: the area already built, if there is one.
- Check the estimate under the presets (see below).
- Tap Use this area.
The banner shows Fetching terrain… and then Stitching terrain… with a progress bar. When it finishes, the terrain appears.
In the picker, red dots are your assets, the blue outline is the project's footprint, and the green outline is terrain that's already been built.
What the area choice gets you
One box sets the terrain detail, the imagery sharpness and the download size, so the picker shows all of them:
| Row | Meaning |
|---|---|
| Area | Size in km². |
| Terrain | Distance between elevation samples, and the elevation tile zoom (for example 4.8 m / sample · z15). |
| Imagery | Ground size of one imagery pixel, and how sharp it gets near the camera. |
| Download | How many elevation tiles are needed, how many are already cached, and roughly how many MB. |
A smaller area gets sharper terrain and sharper imagery. Zoom 15 is the best the elevation data has, and the picker tells you when a smaller area would reach it. Very large areas lose terrain detail to keep the model in memory, and areas over 100 km across can't be built.
Where the terrain comes from
The terrain is built from free public elevation tiles (Mapzen/Tilezen, hosted by AWS Open Data):
- United States: USGS 3DEP, about 10 m resolution.
- Elsewhere: NASA SRTM, about 30 m resolution.
- At sea: ETOPO1 bathymetry.
Heights are orthometric, meaning height above mean sea level. The data credit is shown at the bottom of the 3D view and in Tools → 3D site model.
Move around in 3D
| Gesture | What it does |
|---|---|
| Drag with one finger | Pans across the ground. |
| Pinch | Zooms in and out. |
| Twist with two fingers | Rotates the view. |
| Drag up or down with two fingers | Tilts the view. |
| Double-tap | Zooms in towards the tapped spot. |
The controls on the right, from the top:
- Compass: turns with the view. Tap it to face north again.
- Layers (stacked squares): the display options described below.
- Ruler: measures between two points. See Measure and view elevation profiles.
In the control row, the location button re-frames the view on your current position.
At the bottom left you'll find the imagery detail pill (see below), a scale bar and the data credits.
Tap things in 3D
- A point opens its details.
- A line or area opens the route panel with its elevation profile and a Fly button. See Measure and view elevation profiles.
- Bare ground drops a marker and shows the height above sea level, the slope as a percentage, the direction the slope faces, and the latitude and longitude. Tap the readout to close it.
How assets are placed vertically
Points are drawn as pins, the same as on the map. A coloured ring shows how accurate the position is:
| Ring | Position source |
|---|---|
| Green | RTK fixed |
| Orange-red | RTK float |
| Amber | A receiver without RTK, or better than 1 m vertical accuracy |
| Grey | Phone GPS |
| None | Design or imported point |
Phone GPS heights are often 5–15 m out, which would leave pins floating above the ground or buried in it. So by default, phone-GPS points are snapped onto the terrain. Heights from RTK, other receivers and design files are never moved: they're drawn at their measured height. If the measured height is more than 0.5 m (or more than its own accuracy) off the ground, a line drops from the pin to the terrain.
You can turn snapping off in the layers menu or in Settings → 3D view.
In an asset's details, Ground elevation (terrain) and Δ to terrain show how the measured height compares with the model. If an RTK or receiver height is far from the terrain, the details sheet warns Height disagrees with terrain — check antenna/pole height. That's usually a wrong pole height.
Layers and display options
Tap the Layers button:
Layers
- Routes and lines
- Design / imported
- 3D scans
Terrain (available once the model is built)
Surface: what's drawn on the ground.
Surface Shows Map The app's basemap, with hillshading. The default. Satellite Esri World Imagery. Hillshade Grey shaded relief only. Slope Colour by steepness. Aspect Colour by the direction the slope faces. Elevation Colour by height, from the lowest to the highest point on the site. Vertical exaggeration: 1×, 1.5×, 2× or 3×. This stretches the terrain vertically so gentle slopes are easier to see. Measurements and readouts always use true heights.
Snap phone-GPS heights to terrain: see above.
Contour lines: draws contours on the terrain. The interval is chosen automatically from the site's height range.
Settings → 3D view sets the Vertical exaggeration and Snap phone-GPS heights to terrain the 3D view starts with each time the app opens. Changes in the layers menu last until you close the app.
Imagery detail
The pill at the bottom left shows the imagery zoom and sharpness under the camera, for example z18 · 57 cm/px. With the Slope, Aspect, Elevation or Hillshade surface, it shows the surface's name instead. An up-arrow means the imagery source has more detail than you're currently seeing.
Tap the pill to see:
- Under the camera: the terrain spacing and zoom, the imagery source and its current zoom, the texture size, and Best here, the sharpest the source offers at this spot.
- Imagery detail: Standard or High. Standard loads 512 px images per terrain section, and 1024 px near the camera. High loads 2048 px images for the three sections nearest the camera. That's sharper where you're looking, but uses more data and memory. Switch back to Standard when you're done.
- Rebuild sharper for this site, if the model was built for a much bigger area than the project covers.
- Change working area…, which opens the area picker.
While imagery is loading, a chip shows Imagery 12/25 or Sharpening imagery…. If some images can't be downloaded, it says how many are missing and offers Retry.
Banners
The banner at the top left tells you when the model needs attention. The ⓘ button on any banner opens Tools → 3D site model.
| Banner | What to do |
|---|---|
| Choose the 3D area | No area chosen yet. Tap Choose. |
| Build 3D site model | An area is chosen but not built. It shows the size, terrain spacing and download size. Tap Build, or Area to change the box. |
| Site grew beyond the 3D model / The 3D area changed / 3D model settings changed / Terrain is out of date | The model needs rebuilding. Tap Rebuild. Cached tiles are reused, so only what's missing downloads. |
| Terrain failed | The build failed, with the reason. Tap Retry. |
| No connection | Terrain needs a one-time download. Tap Retry when you have signal. |
| Assets outside the 3D area | You've collected beyond the model's edge. Tap Grow to extend it to cover every asset. It shows how many extra MB that takes. |
| Sharper terrain available | The model was built for a much bigger box than this project needs. Tap Rebuild to build at a finer resolution for the project's own area. |
If you pan off the edge of the terrain, a Beyond the site model chip says Terrain isn't built here yet. Tap Expand to grow the model to include the spot you're looking at.
The model never grows on its own; it only grows when you tap one of these. Growing keeps every tile already downloaded.
Tools → 3D site model
Tools → 3D site model (in the Map section) manages the model for the active project. The row shows its status: Not built, Building…, Ready, Stale, Failed or Offline.
Status Shows whether the model is built, and once it is: Resolution, Grid size in samples, Heights (lowest to highest, in m above sea level), Tiles, Size on disk and Fetched date. Shared terrain cache is the elevation data cached for all projects.
Working area (or Area (not chosen yet)) The Area size, its Centre, and the same estimate as the picker, with:
- Choose area on the map… / Change area on the map…: opens the area picker.
- Use current map view: builds for whatever the 2D map is showing.
- Grow to cover every asset: shown when assets fall outside the model.
Keep below-sea-level terrain Off by default. Public elevation data stores the sea bed as negative heights, which would make a coastal site look like it sits beside a trench, so heights below sea level are raised to sea level. Turn this on only if your site really is below sea level.
Actions
- Build site model / Rebuild site model
- Cancel build, while one is running.
- Refresh from source: deletes this area's cached elevation tiles and downloads them again.
- Re-centre frame origin: resets the project's local 3D origin to the centre of what's currently collected. The origin is fixed the first time a model is built, so that terrain exports made at different times line up. After re-centring, new exports use the new origin.
- Delete cached site model: removes this project's model from the phone, after you confirm. Terrain can be rebuilt at any time with a connection.
Export Terrain OBJ files. See Export the terrain.
Attribution The full data credit and a Data sources and attribution link.