Point cloud to floor plan
Automatic point cloud to floor plan
Open a point cloud from any scanner and get a to-scale, dimensioned floor plan, with sections and elevations, in one run and entirely offline. No capture app, no trajectory, no panoramas and no upload: Neurones 3D (N3D) reads LAS, LAZ, E57 or PLY, finds the rooms, the walls and the openings, and draws the set, ready for CAD as DXF, PDF and SVG.
By Dr. Florent Poux, 3D Geodata Academy · Updated
At a glance
Short statements, each one checkable. Where there is a number, it was measured, and the guides say on what.
- N3D draws a floor plan from a point cloud automatically: one command, Process › Floor plan…, with nothing traced by hand.
- It reads the formats scanners write: LAS, LAZ, COPC, E57, PLY, PCD and ASCII. An IFC model can be drawn as well.
- It runs offline on a Windows PC. Nothing is uploaded and no account is needed.
- On a 43 million point survey (S3DIS Area 4) it found 42 spaces and wrote the plan, six sections and elevations, 21 files and the GIS layers in 1.0 s.
- Walls are drawn between their two measured faces; wall thickness is within about ±30 mm at the default voxel.
- Drawings use ISO 3098 lettering, ISO 5455 scales (1:20 to 1:1000 when fitted to the sheet; 1:20 to 1:500 when set by hand), an ISO 5457 frame and an ISO 7200 title block.
- Each drawing is saved as DXF (R2000, metres at 1:1, real dimension entities), PDF 1.4 and SVG, and the building as GeoJSON and Shapefile.
- On every test sheet (the IFC model storey by storey and S3DIS Area 4, A3 and A1), the scale bar, north arrow, legend and section marks collide with nothing: from up to 107 collisions on a sheet to 0, checked by an automated overlap test.
How the plan is drawn
From points to rooms
The cloud is first decomposed into planes, cylinders and clusters. Horizontal planes give the floors and ceilings, and so the storeys; vertical planes give candidate walls. The free space between floor and ceiling is flooded and split at the doorways, which finds each room as a volume of air rather than as a box, so a table does not wall off the room it stands in.
From rooms to a drawing
Walls are extracted with their two faces, joined at corners and tees, and bridged where they are collinear. Openings are classified from vertical occupancy: a door where the wall is open to the floor, a window where it is open above a sill. The plan is then set on a standard sheet at a standard scale, dimensioned (a wall earns a station on a façade’s chain only if it reaches that side), and given its title block, legend, scale bar and north arrow.
Sections and elevations, for free
Everything a section needs was measured on the way to the plan. A cutting plane through the building draws the walls it meets cut, with everything beyond in projection; moved past the façade, the same plane gives an elevation. The planes are placed where they cross the most rooms and openings, and the plan carries their marks.
Questions
Does N3D draw a floor plan from a point cloud automatically?
Yes. Process › Floor plan… decomposes the cloud, builds a scene graph, finds the rooms by flooding the free space, extracts the walls and their openings, and draws the dimensioned plan, sections and elevations. On a 43 million point survey the whole set takes about a second. You can then move dimensions, labels and marks by hand.
Which scanners and file formats work?
Any scanner whose data arrives as LAS, LAZ, COPC, E57, PLY, PCD or an ASCII point file: terrestrial, mobile or handheld. The plan is drawn from the points alone, so no trajectory, panoramas or capture app are needed.
What does the drawing set contain?
A plan per storey with walls in poché, doors with their swing, windows with their glass, dimension chains outside every face, room names, areas and levels, a legend, a scale bar above the title block and a north arrow; plus automatic sections and elevations. Each is saved as DXF, PDF and SVG, and the building as GeoJSON and Shapefile.
Can it save DWG?
No. DWG is not written: its specification is not published and the only open library is LGPL, which N3D’s permissive-only licence policy excludes. DXF R2000, which AutoCAD and every CAD package open, is written instead, with real dimension entities and ISO 13567 layer names.
What are the limits?
A wall the scanner did not see cannot be drawn. Wall ends are joined within 0.9 m, and a wall meeting another’s side within 2.2 m; wider gaps are left as surveyed. A sprawling space riddled with furniture is lettered Open plan rather than called a room. Levels are on the scan’s datum.
Is it free?
Drawing and previewing the plan are free. Saving the drawings (DXF, PDF, SVG) and the GIS layers is part of Pro.
The guides behind it
Each guide gives the menu path, the steps, the command-line equivalent and the limits.
component and its primitive_kind.
Measure and cut
2-D sections and orthoimages
Cut a slab through the cloud at any height, or a vertical section at any angle, see it live in 3-D, lock into an orthographic view to read it like a drawing, and save it as an image at full point density.