Splats to deliverables
Gaussian splat to floor plan, CAD and measurements
Neurones 3D takes a capture from Gaussian splat to floor plan, CAD and measurements through one chain, offline on your own PC: convert the splats to a point cloud, set the scale if the capture is not metric, then measure, cut sections, classify and draw a dimensioned plan, saved as DXF, SVG and PDF.
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.
- Process › Convert to point cloud… turns a PLY or SPZ splat capture into a real point cloud by oriented disc sampling, 5 million points by default.
- Scale comes from the capture. There is no automatic metric scale for splats: rescale the layer by hand in its reposition window.
- The Measure tool reads point coordinates, 3D, horizontal and vertical distances, areas and volumes.
- The 2D section tool cuts plans and sections through the cloud and saves orthoimages up to 8192 px.
- Process › Floor plan… draws a dimensioned plan with sections and elevations from any cloud N3D can open, saved as DXF R2000, SVG and PDF 1.4.
- The published floor plan and classification figures were measured on laser scans; no accuracy figure exists for a converted splat capture, so check a known dimension.
- Segmentation, classification and a LAS or PLY export work on the converted cloud as on any scan.
- Everything runs offline. Running every step is free; writing drawings and computed columns out needs a paid edition, bought once.
The chain from splats to a drawing
Why splats become points first
A splat capture looks finished, but it is hard to hand over: practitioners in architecture and construction have described splats as hard to measure and short of a clean deliverable (AEC Magazine, December 2025). N3D’s answer is to turn the splats into what the rest of its pipeline already works on. Process › Convert to point cloud… samples each splat’s surface as an oriented disc and writes a real point cloud: 5 million points by default, from 0.2 to 50 million, with floaters and noise removed. Segmentation, classification, sections, the floor plan and export all apply to it, exactly as to a scan.
The chain, step by step
| Step | Where | What comes out |
|---|---|---|
| Open the capture | File › Open… | the splats, PLY or SPZ |
| Merge a second capture (optional) | Process › Merge splat captures… | one scene from two captures |
| Convert | Process › Convert to point cloud… | a point cloud |
| Set the scale | Scene pane › reposition › SCALE | the cloud at the size you give it |
| Measure and cut | Measure tool · 2D sections & floor plans | distances, areas, volumes, orthoimages |
| Classify (optional) | Properties › AI Analysis › N3D Classifier | a class and a confidence per point |
| Draw | Process › Floor plan… | plan, sections and elevations: DXF, SVG, PDF |
| Export the cloud | File › Export point cloud… | LAS, PLY, CSV, USD or a web viewer |
Converting replaces the loaded splats, so save the project first if you will want them back. Merging two captures drops higher-order spherical harmonics, and the window says so first.
Scale is the capture’s, until you set it
A splat capture carries whatever scale the tool that made it gave it, and N3D does not guess. Metric anchoring for splats is not built. Measure a dimension you know, such as a door width, and rescale the layer uniformly in its reposition window before you draw or export anything that will be measured. Registration to a laser scan will not do it for you: alignment moves and turns a layer but does not scale it. A layer rescaled by hand is exported without a coordinate system, because the stamp would no longer be true, and the plan’s levels are on the capture’s own datum.
What has been measured, and on what
The numbers N3D publishes for these steps were measured on laser scans. On the 43 million point S3DIS Area 4 survey the floor plan found 42 spaces and wrote the plan, six sections and elevations, 21 files and the GIS layers in 1.0 s, with wall thickness within about ±30 mm at the default voxel. The classifiers’ held-out accuracies are also on scans. No accuracy figure has been measured for a floor plan drawn from a converted splat capture, and this page does not claim one. The chain is the same; the input is not. A wall the capture did not see cannot be drawn, and where the classifier is unsure, its per-point confidence shows it.
What leaves the program
Each drawing is saved as DXF R2000 (model space in metres at 1:1, with real dimension entities and ISO 13567 layer names), SVG in real paper millimetres and PDF 1.4 at the sheet’s true size, lettered to ISO 3098. The building is also written as GeoJSON and Shapefile. The section tool saves a PNG orthoimage, a picture of the points rather than a drawing. The cloud itself leaves as LAS, PLY or CSV with its class and ids. DWG is not written, and a mesh of the capture is a separate route, described in Gaussian splatting to mesh.
Questions
Can I make a floor plan from a Gaussian splat?
Yes, through a point cloud. Convert the capture with Process › Convert to point cloud…, set its scale if it is not metric, then run Process › Floor plan…. The plan, sections and elevations are drawn from the converted points and can be saved as DXF, SVG and PDF.
Can I measure distances in a Gaussian splat?
Yes. Measuring in a splat capture is free, and the Measure tool reads distances, areas and volumes. The numbers are in the capture’s own units, which are metres only if the capture was made at metric scale.
Is a Gaussian splat capture to scale?
Not necessarily, and N3D cannot tell automatically: metric anchoring for splats is not built. Measure a dimension you know, then scale the layer uniformly by hand in its reposition window. Alignment to another cloud is rigid and does not rescale.
How accurate is a floor plan drawn from a splat capture?
There is no published figure. The wall thickness of about ±30 mm was measured on a laser scan at the default voxel. A converted splat cloud is a sample of the splats’ surfaces, so its accuracy is the capture’s; check it against a dimension taken on site.
Can I export a Gaussian splat to DXF or CAD?
Not the splats themselves: the drawing is made from the converted point cloud. The floor plan is saved as DXF R2000 in metres at 1:1 with real dimension entities, as SVG and as PDF, and the building as GeoJSON and Shapefile. Saving them needs a paid edition. DWG is not written.
Can a splat capture be classified?
Once converted to points, yes: the same classifiers run on it. They were trained on scans, and a capture unlike the training data will score lower, so colour by the confidence column to see where the model hesitated.
What is free and what needs a licence?
Opening, converting, measuring, sectioning, classifying and previewing the floor plan are free. Saving the drawings, a PNG orthoimage and the computed columns on an export needs a paid edition, bought once, with no subscription.
The guides behind it
Each guide gives the menu path, the steps, the command-line equivalent and the limits.