Help & guide

Lidar Extractor turns your Raven (JMK7) scans into usable data on macOS: cloud extraction, 3D viewer, measurements, floor plans, and Gaussian Splatting export. Here is how to use it all.

1. Open a scan

• Raw ROS Bag (the device folder): the app rebuilds the cloud with LiDAR SLAM, no .amap needed. Default source.
• Filtered .amap: direct cloud decoding (click “Source” 10 times to reveal it).
• Cloud file (XYZ / PLY / E57): the “Open a cloud…” button to view it directly.
• Recents: a menu reopens your last 10 files/folders.

2. Export the clouds

Tick the formats you want — XYZ, PLY, E57 (optional camera color for raw scans) — then click Extract. Files are written next to the source.

3. The 3D viewer

Click View to open the cloud. Mouse controls:

• Left-drag: rotate (the spot you grab follows the cursor)
• Right-drag: pan
• Scroll / trackpad pinch: zoom
• Trackpad rotate: roll · double-click: recenter

Bottom: preset views (Iso, Top, Front…) and “Center”. Top-left: color (File, Height, Gray, Turbo) and the layers.

4. The 7 tools

• Slice: horizontal or vertical section of the cloud (adjustable height, thickness).
• Crop: click around the area to keep, validate → the outside is removed.
• Eraser: erase points with the mouse (adjustable brush size), then “Apply”.
• Measure: distances and areas (m / ft), automatic room detection (m²).
• Draw: place points (snapped to walls) to draw lines.
• Lock: lock the orientation (ideal in top view to trace).
• Realign a part: puts a room that drifted back where it belongs — lasso it, then move and rotate it by hand.

4b. Realign a drifted part

In small rooms (tiled bathrooms, narrow corridors, cluttered rooms) the SLAM sometimes loses its bearings: the room ends up shifted and rotated relative to the rest of the scan. The Realign a part tool puts it back by hand.

1. Switch to the Top view: the lasso spans the full height, so it takes the whole room.
2. Pick Realign a part, click several points around the misplaced area to enclose it, then Confirm selection.
3. The selected part appears in orange over the original cloud. Drag the centre disc to move it, the disc on the ring to rotate it. The offset is shown live (metres and degrees); the two Fine rotation buttons adjust by a quarter of a degree.
4. Apply: the correction is applied to the full cloud, not just what is on screen. When you close the viewer, the app offers to save under a new name.

What to aim at: line up the walls, not the furniture. A properly realigned wall shows as a single line again instead of a doubled one. “Reset” cancels the current move, “Another part” starts a new selection.

Note: the tool only does horizontal translation and rotation about the vertical — which is exactly what drift does, since level is held by the scanner’s inertial unit. To avoid the problem in the first place: do not step into a small room in the middle of your path, and avoid or cover mirrors.

5. Measuring (distance & area)

Measure tool → Distance mode (2 clicks) or Area mode (click the corners then “Finish”). The point always snaps to the nearest visible point. Pick units m · m² or ft · ft² for your region.

6. Layers & saving

Saved cuts appear as layers on the left; you switch between them without changing window. The disk button saves the displayed cloud: same name = replace the original, new name = new file. Your cuts are remembered per file and restored when you reopen it.

7. Gaussian Splatting (photorealistic)

Unlock it (10 clicks on “Gaussian Splat”), it is exclusive of the other formats and launched by the button:

• Photos for Polycam: extracts the photos to upload to Polycam (the cloud does the rest).
• Dataset for Brush: images + poses + init cloud, to open in Brush (local training on the Apple Silicon GPU).

8. Full guide: build a floor plan

Tip: for a clean plan, remember to clean the point cloud before tracing — the less noise and furniture, the better the walls stand out.

1. Crop — Crop tool: click around the area to keep (the building), then validate. Everything outside (vegetation, surrounding ground, stray points) is removed.
2. Clean with the Eraser — Eraser tool: brush over isolated stray points (noise, reflections), adjust the brush size, then “Apply” to remove them for good.
3. Slice — Slice tool: take a horizontal section at wall height (≈ 1.2 m) with a thin thickness (± 5 to 15 cm). You get a slice showing the walls from above.
4. Clean the interior — Use the Eraser again inside the slice to erase the furniture and interior objects (tables, chairs, shelves) that fell into the slice: only the walls should remain.
5. Trace the walls — Switch to Top view and enable Lock. Draw tool: click along the walls (points snap to them), close each room. You can also “Detect walls” automatically.
6. Export to DXF — Export menu → DXF (3D lines) for your drawing, or DXF (2D plan) of the slice. Open the file in your CAD software (AutoCAD, etc.).

Tip: once the walls are traced (or detected), the Measure tool’s room detection (m²) computes the areas automatically.

9. Automatic 2D floor plan (new in 0.6.0)

In the 3D viewer, the 2D plan button (left tool rail) automatically draws the property plan from the cloud: detected walls, doors, and rooms with their areas. Detection filters furniture by itself — for a specific storey, isolate it first with the Slice tool. Since 0.7.0, 45° corner cuts (Haussmann-style angles) and curved walls (rotundas, bow windows) are detected too — arcs are exported as true ARC entities in DXF.

• Full editor: draw walls (adjustable thickness, Ctrl = forced straight line, alignment guides, “continuous wall” mode), place doors and windows with dimensions (width × height, sill for windows) and swing direction (left/right, inward/outward), name rooms (multilingual predefined names, auto-numbering: Bedroom 1, Bedroom 2…), place dimension lines (set on the 3rd click), move or erase any element.
• Cloud underlay: the point cloud shows under the drawing, aligned (eye to hide it), to correct the plan against real data.
• Automatic saving: the plan keeps all your edits and reopens as-is; the “Reset” button re-runs detection.
• Professional exports (an export_plan folder next to the scan): PDF at standard scale (1:50, 1:100… or US scales) with a title block, A4/A3/Letter/Tabloid paper; SVG; multi-layer DXF (walls, doors, windows, names, rooms, cloud) for AutoCAD. Units in meters or feet/inches.

10. Georeferencing, LAS & map (new in 0.5.0)

For Raven Max / RTK scans, choose LAS (georeferenced) in Export. The app places the cloud in real-world coordinates and picks the right system automatically (UTM/EPSG by country).

• Centimeter (PPK): if the scan has no on-board base, the app automatically downloads the nearest EUREF reference station (anywhere in Europe) for centimeter post-processing. If no station is close enough, it stays at meter level and tells you.
• Map view: the 🗺 button shows the cloud over an OpenStreetMap or satellite background, zoomable.
• .las files: the 3D viewer opens .las clouds (yours or from other software) like any other.
• Livox scanners: scanners with a Livox LiDAR (e.g. Eagle) are now supported alongside Hesai (Raven) — the sensor is detected automatically.

11. Remote mode — control the Raven (new in 0.8.0)

Two icons at the top of the window give Wi-Fi access to the scanner, no SD card: ☁ Raven scans and the Raven icon (setup).

• Setup: installs the control agent on the scanner in one click. The install is additive and reversible (it only adds its own files, without touching the Raven's system); the « Uninstall » button restores the scanner to its original state. A compatibility check (Simple/Max model, architecture, OS) runs first.
• Raven scans: connects to the scanner, lists your scans and downloads them to the computer, showing the transfer time. « Open in Lidar Extractor » then moves on to extraction.
• Raven screen: shows the scanner's real screen and lets you control it with the mouse, remotely.
• Mobile app — Lidar Extractor Remote (iOS + Android, available): control the Raven from your phone (auto-detection, scanner status, start a scan, remote screen). Prerequisite: first install the control agent on the Raven via the desktop app (« Setup » above); without it the phone cannot connect. ⚠️ This app only works with a Raven scanner (not an Eagle or any other device). If you run into trouble, the app can send its diagnostic logs so our support can help.
• How to install:
  • iPhone / iPad (TestFlight beta): install the free TestFlight app from the App Store, open this link on the device — testflight.apple.com/join/f9cfQvHd — then tap Accept and Install.
  • Android: download the APK from the « 📱 Android » button on the home page, then open it to install (allow unknown sources if prompted).

12. Cloud extraction & upload from the Raven (new in 0.9.16)

Your scans can now be processed on our servers (same GLIM engine as the app: SLAM, camera colorization, PLY/LAS exports) — and can even get there without a computer.

• Web portal: on your account, "New project" accepts your scanner's zipped folder. 1 free extraction per day, then 1 token each (the same tokens as the Gaussian Splat cloud). Result: colorized PLY/LAS cloud + online viewer with length and area measurements.
• Raven Link — upload without a PC: enable "Cloud upload of scans" in the app (Raven screen). Whenever your Raven has Internet, it lists its scans in the My Raven tab of your account; tick them and it uploads by itself (automatic resume, SHA-256 integrity check), then one-click "Extract". Received files are kept for 7 days.
• "GLIM Cloud extraction" button in the app (below "Extract"): it will send your raw scan straight to the server queue — rolling out progressively, write to us if you want early access.

13. Ground control points (GCP) — new in 0.9.18

Fit the cloud onto points whose coordinates you know, and above all get the error left on each one. That table of errors is what you hand to your client: a cloud that has been moved, with no figures, commits nobody.

The GCP tool (target icon) in the viewer toolbar.

Two ways to bring the points in

• Your scanner's marks. On the Eagle and the Raven, placing the tip on a mark and pressing the button records a timestamp (controlpoint.txt). The app reads the position from the scan trajectory: more accurate than clicking in the cloud, since the mark was touched by the tip. All that is left is entering the surveyed coordinates (double-click the row). The scan must have been extracted with the app, which writes the trajectory next to the cloud.
• A points file: name, E, N, Z, one line per point. Commas or semicolons, with or without a header, decimal comma accepted. An unreadable line is reported — never silently swallowed. You then click each mark in the cloud.

How it goes

1. Load the points, pick them if needed.
2. Compute — nothing moves. You get the mean error (RMS) and the error on each point; past 5 cm the row turns red.
3. One point far above the others is not a wrong cloud: it is a misplaced click or a mistyped coordinate. Fix it, compute again.
4. Apply once the errors suit you. The exported LAS then carries absolute coordinates and its EPSG code.
5. CSV or PDF report: date, coordinate system, model, error per point.

Check points

Clicking a row's role switches it to check: it leaves the computation and only serves to judge it. That is the sole independent verification — a point that produced the fit cannot assess it. The app shows both errors separately, and warns you when there is no check point at all.

Fitting models

• Yaw + translation (default): the cloud rotates about the vertical. A LiDAR scan is already levelled by gravity; a free rotation would tilt it to absorb a mistake in Z.
• 3D rotation + translation: when you accept that the cloud may be tilted.
• Similarity: adds a scale factor. Use it knowing that a scale other than 1 on a LiDAR scan signals a measurement problem — it hides it, it does not fix it. The app shows the departure in ppm.

Worth knowing

• Pole height: the trajectory gives the position of the device, not of the tip on the ground. Enter the distance between them, otherwise every Z is off by that amount — an error invisible in the horizontal figures.
• You need at least 2 points for the default model, 3 for the 3D models, and above all well spread points: three marks bunched in one corner give an excellent RMS and a cloud askew at the far end.
• The error will not go below the scan resolution: if points are 2 cm apart, aiming for the millimetre is meaningless.