A VSCode extension that opens CityGML Level-of-Detail 2 (LoD2) files directly as an interactive 3D scene — no external tools required.
Features
3D WebGL rendering — buildings, bridges, and tunnels appear automatically when you open any .gml file
Surface colours — walls grey, roofs red, ground surfaces dark grey; bridges in sandy brown, tunnels in slate
Orbit navigation — left-drag to rotate, right-drag to pan, scroll to zoom (no momentum/damping)
Top-down view — toggle button switches to an orthographic plan view (pan + zoom only)
Click to inspect — click any surface to highlight the whole object orange and display its gml:id and all gen:stringAttribute properties in a side panel
Deselect — click the selected object again to clear the selection (dragging to orbit never triggers a deselect)
Switch to text — "View XML Source" button in the toolbar opens the file as plain text; right-click the tab → Reopen with CityGML 3D Viewer to switch back
Usage
Open a folder containing a .gml CityGML file in VSCode
Click the file in the Explorer — the 3D viewer opens automatically as a custom editor tab
Use the toolbar buttons at the top-left to toggle the view, reset the camera, or open the raw XML
Click any surface to see its properties in the panel at the top-right
If a .gml file opens as plain text instead, right-click the file → Open With… → CityGML 3D Viewer.
To switch back from text to the viewer, right-click the editor tab → Reopen Editor With… → CityGML 3D Viewer, or use the command palette: CityGML: Open 3D Viewer.
Keyboard shortcuts
Action
Windows / Linux
macOS
Open 3D Viewer for active .gml file
Ctrl+Shift+V
Cmd+Shift+V
Supported format
The extension targets CityGML 1.0 / 2.0 files with LoD2 geometry.
