# Desktop viewer: surfaces, bare terrain and contours from a point cloud

> Build the full surface, then the bare terrain under houses and trees, check it against an official model, trace contours and export them.

Page: https://finitor.cl/learn/desktop-surfaces

Video: https://finitor.cl/learn/desktop-surfaces-en.mp4 — A hillside village in Switzerland, airborne LiDAR swissSURFACE3D coloured with SWISSIMAGE, © swisstopo. Against swisstopo's official terrain model swissALTI3D, the bare terrain is off by 1.6 m with the default filter and by 0.54 m once the largest object is set to the widest building, 40 m.

## Surface and terrain

1. In Tools, Surfaces and contours, choose Grid and click Build surface: everything the scanner hit, roofs and treetops included (a DSM).
2. Tick Bare earth only, choose a ground filter (Auto) and build again. Set Largest object to the widest building to see through it, and build once more.

## Contours and exports

1. Set the contour interval and click Trace contours; in Compare, vs DTM colours every point by its height above the terrain.
2. Export and save writes the terrain as GeoTIFF and the contours as DXF, for a GIS or a CAD program.

## More about Finitor Cloud

- [Finitor Cloud: photogrammetry and LiDAR in the cloud](https://finitor.cl/)
- [Cloud photogrammetry](https://finitor.cl/fotogrametria-en-la-nube)
- [LiDAR classification](https://finitor.cl/clasificacion-lidar)
- [Point cloud viewer](https://finitor.cl/visor-nube-de-puntos)
- [Pricing](https://finitor.cl/pricing)
- [Features](https://finitor.cl/features)
- [Measured accuracy](https://finitor.cl/accuracy)
- [Cameras and files it reads](https://finitor.cl/cameras)
- [Demonstration: a finished survey](https://finitor.cl/demo)
- [How it works](https://finitor.cl/how)
- [Tutorials](https://finitor.cl/learn)
- [Finitor Desktop, the desktop application](https://finitor.cl/viewer)
- [Contact](https://finitor.cl/contact)
- [Terms and privacy](https://finitor.cl/terms)