Build deliverables
Vector layers and GIS
Put the design drawing beside the survey of what was built - GeoJSON, Shapefile, DXF, SVG or CityGML over the scan, in the same frame - with a coordinate-system check, and write the building back out as GIS data.
Reading and overlaying are free. Writing GeoJSON and Shapefile is Pro.
Part of Point cloud to CAD (DXF), Point cloud to topographic map.
When to use it
To compare a design drawing or a cadastral layer with the scan, to check a building footprint, or to take the floor plan’s building into a GIS as data rather than as a picture.
Step by step
- Drop a GeoJSON, Shapefile, DXF, SVG or CityGML file on the window, or use File › Add Layer…. It lands where its coordinates say.
- Open File › Vector layers… to manage the layers: + Add file…, and In 3-D, On the plan and Attributes on hover, all on by default.
- Read the coordinate-system line: The scan is in … or The scan claims no coordinate system. If a layer is in a different system from one already loaded, N3D says they will not line up and to reproject one first.
- For each layer, set the Line width, the Height (As given, or Flat at a level; flat files default to 1 cm above the floor), and nudge it in X, Y and Z if needed; Reset undoes the nudge.
- Frame flies to the layer; Save as… writes it as GeoJSON or Shapefile; Remove takes it out of the scene.
What it was measured at
Coordinate systems are read from LAS GeoTIFF keys, the OGC WKT record and LAS 1.4 extended records, and a clash between a layer and the scan is reported rather than drawn wrong.
From the command line
# write the building from a floor plan run as GIS layers
n3d-render-cli floorplan --input area4.las --out area4 --vector area4.geojson --vector area4.shpLimits, stated
- Only GeoJSON and Shapefile are written; the others are read-only.
- DWG and DGN are refused: save them as DXF, or convert a folder with the ODA File Converter.
- On a scan with no coordinate system, a vector layer is fitted onto it, and N3D says the placement is a fit and not a coordinate.
Related questions
Can it read or write DWG?
No. DWG and DGN are proprietary binary formats: DWG’s specification is not published, and the only maintained open reader is LGPL, which N3D’s permissive-only licence policy excludes. So neither is read nor written, and N3D says so. Save the drawing as DXF from the program that made it, or convert a folder with the free ODA File Converter; N3D reads DXF fully and writes drawings as DXF R2000 (which AutoCAD and every CAD package open), PDF and SVG.
Does it keep the coordinate system?
Yes. It is read from LAS GeoTIFF keys, the OGC WKT record and LAS 1.4 extended records, carried into reports, and stamped on a LAS export as long as the geometry is still the source’s. A cloud that was moved by hand is written without it, because the stamp would no longer be true. Vector layers are checked against it and a clash is reported.
Which formats can it write?
Point clouds as PLY, LAS and CSV, a USD stage (.usda) or a self-contained web viewer. Meshes and voxels as glTF / GLB. Drawings as SVG, DXF (R2000) and PDF 1.4. Vectors as GeoJSON and Shapefile. Rasters as GeoTIFF and ESRI ASCII grid. Reports as HTML. Images as PNG or JPEG and flythroughs as MP4. Writing results out is a Pro feature.
More in the FAQ.