Survey Layers & Overlays

Once your surveys are processed, their outputs appear as layers on the CesiumJS 3D globe. The Layers tab in the floating panel gives you full control over what is visible, how transparent each layer is, and which base map sits beneath your data.

Survey Layers

Each completed survey creates up to three layers in the Layers tab, depending on which outputs were uploaded or processed:

Orthophoto Overlay

The orthophoto is displayed as a 2D image overlay draped on the globe terrain. When enabled, it replaces the base map imagery in the area covered by the survey.

Controls:

• Toggle — a switch to show or hide the orthophoto overlay
• Opacity slider — adjust transparency from fully opaque to fully transparent, letting you blend the orthophoto with the base map or other layers beneath it

💡 Tip

Set the orthophoto opacity to around 70-80% to see the survey image while still getting a sense of the underlying terrain contours from the base map. This is useful when checking how well the orthophoto aligns with known features.

Point Cloud 3D Tileset

The point cloud is displayed as a 3D tileset — millions of coloured points rendered in three dimensions on the globe. You can orbit, zoom, and tilt the globe to view the point cloud from any angle.

Controls:

• Toggle — a switch to show or hide the point cloud

Point clouds use level-of-detail streaming, so nearby points are rendered at high density while distant areas use fewer points. This keeps performance smooth even for large datasets.

DEM Availability Indicator

The DEM is not a visual layer itself — it is used internally by measurement tools (elevation profile, volume calculation, gradient, grade check). The Layers tab shows a status indicator for DEM availability:

• Available (green) — the DEM is loaded and measurement tools that require elevation data will function
• Not available (grey) — no DEM was uploaded for this survey; elevation-dependent tools will not be available

ℹ️ Did you know?

The DEM does not appear as a visible overlay on the globe. Its purpose is to provide elevation data to the measurement tools. If you need to visualise elevation differences, use the measurement tools such as Elevation Profile or the Cut/Fill Heat Map.

Base Map Selection

The base map is the background imagery shown on the CesiumJS globe beneath your survey layers and design surfaces. Three options are available:

Switch between base maps using the selector at the top of the Layers tab. The change applies immediately.

💡 Tip

Use the Satellite base map when comparing your orthophoto to recent commercial satellite imagery. Switch to Outdoor when you need to see contour lines and terrain context around your survey area.

Multiple Surveys and Layer Stacking

A site can have multiple surveys, each with its own set of layers. All survey layers appear in the Layers tab, grouped by survey name and date.

When multiple orthophoto overlays are enabled simultaneously, they stack in chronological order — the most recent survey appears on top. This is useful for comparing site progress over time by toggling between surveys or adjusting opacity to blend them.

Stacking Order

• The most recent survey's layers render on top
• Older survey layers render beneath
• Design surfaces render above all survey layers (see Layer Management)
• The base map is always at the bottom

Comparing Surveys

To visually compare two surveys taken at different times:

1. Enable the orthophoto for both surveys
2. Set the top (newer) survey's opacity to approximately 50%
3. The blended view shows changes between the two captures — useful for tracking earthworks progress, vegetation changes, or construction advancement

Layer Visibility Toggles

Every layer has a simple toggle switch — on or off. Turning a layer off removes it from the globe display but does not delete any data. You can toggle layers on and off freely without any processing delay, as the data remains loaded and ready.

ℹ️ Did you know?

Layer visibility settings are session-based. When you leave a site and return later, layers reset to their default state (orthophoto on, point cloud off for the most recent survey). Your opacity adjustments also reset between sessions.

What's Next?

• Layer Management — manage design surface layers alongside survey layers
• Floating Panel & Tabs — understand the panel interface where layers are controlled
• Creating Surveys — add more surveys to build a timeline of site progress
• Importing Processed Data — upload pre-processed outputs from external software