scan2mesh

Convert, view, inspect, and split lidar point cloud files. Mesh output supports both visualization (smooth, watertight) and precision (geometrically faithful) workflows.

Features

• Input formats: LAS, LAZ, E57, PLY, PCD, XYZ, PTX, PTS
• Output formats: OBJ, glTF, GLB, STL
• Interactive 3D viewer with per-scan coloring (E57)
• Metadata inspection, per-scan splitting
• Interruptible pipeline — Ctrl+C exits immediately even during Open3D C++ calls
• Animated progress bar during long stages

Installation

Requires Python 3.10 – 3.12. Open3D does not yet ship wheels for Python 3.13, and numpy is pinned to <2 for Open3D ABI compatibility.

git clone https://github.com/larsenTFG/scan2mesh.git
cd scan2mesh
pip install -e .

# Optional: E57 support (requires C++ build tools on first install)
pip install -e ".[e57]"

Sample E57 files are available in examples/ to try out the tool.

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Commands

scan2mesh has four subcommands. The convert command is the default — it can be omitted from the command line.

Command	Purpose
convert	Point cloud → mesh (default)
view	Open an interactive 3D viewer
inspect	Show file / per-scan metadata
split	Split an E57 file into per-scan files

Run any command with --help for the full option list.

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convert

Convert a point cloud file to a mesh.

scan2mesh convert <input> <output>
scan2mesh <input> <output>              # 'convert' is implicit

Convert runs in one of two reconstruction modes, each with three quality presets:

Visualization mode — --mode visualization (default)

Smooth, watertight meshes for viewers, web, and game engines. Uses Poisson reconstruction, which fills gaps and produces render-ready surfaces.

Options

Flag	Description	Default
-q, --quality {low,medium,high}	Preset within the mode.	medium
-f, --target-faces INT	Cap the output triangle count.	Preset
--poisson-depth INT	Poisson octree depth.	Auto (scene-scaled)
--voxel-size FLOAT	Absolute voxel size.	Auto
--color / --no-color	Vertex color transfer.	--color

Presets

Preset	Voxel (× spacing)	Poisson depth floor	Target faces
low	8×	7	500K
medium	4×	9	2M
high	2×	10	Unlimited

Examples

# Quick preview
scan2mesh examples/trimble.e57 preview.glb -q low

# Web-ready mesh with a fixed polygon budget
scan2mesh examples/pump.e57 pump.glb -q medium -f 250000

Precision mode — --mode precision

Geometrically faithful meshes — only triangulates where points were actually measured. Uses Ball Pivoting, which leaves real gaps as holes rather than hallucinating surface.

Options

Flag	Description	Default
-q, --quality {low,medium,high}	Preset within the mode.	medium
--max-deviation FLOAT	Max mesh deviation from source (mm).	Preset
--bpa-radii "a,b,c"	Ball Pivoting radii as multiples of point spacing. More/larger values bridge more gaps at the cost of runtime.	1,2,4
--voxel-size FLOAT	Absolute voxel size.	Auto
--color / --no-color	Vertex color transfer.	--no-color

Presets

Preset	Voxel (× spacing)	Normal neighbors	Decimation
low	3×	30	≤ 5 mm deviation
medium	1.5×	50	≤ 2 mm deviation
high	1× (dedupe only)	50	None

Examples

# Keep every measured point, transfer scanner colors
scan2mesh examples/pump.e57 pump.glb --mode precision -q high --color -v

# Tight deviation budget for QA / metrology
scan2mesh input.e57 out.obj --mode precision --max-deviation 1.0

# Extend BPA radii to bridge sparse scan regions
scan2mesh input.e57 out.glb --mode precision -q high --bpa-radii 1,2,4,8 --color

Options available in both modes

Flag	Description
--method {poisson,ball_pivoting}	Override reconstruction algorithm (decouples from mode default).
--scans "0,2,3"	For E57: include only these scan indices.
--no-outlier-removal	Skip the outlier filter (faster; safe for clean scans).
-v, --verbose	Per-stage logs including live elapsed time.

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view

Open an interactive 3D viewer for a point cloud file.

scan2mesh view <input>

Uses Open3D's visualizer. For multi-scan E57 files, scans can be coloured and isolated at runtime.

Options

Flag	Description	Default
--voxel-size FLOAT	Downsample before display (handy for huge clouds).	No downsampling
--background {dark,light}	Viewer background color.	dark

Keybindings (E57 with multiple scans)

Key	Action
S	Color points by scan index
1–9	Isolate an individual scan

Examples

# View the whole file
scan2mesh view examples/trimble.e57

# Downsample a huge cloud before displaying
scan2mesh view cloud.ply --voxel-size 0.05

# Light-background view
scan2mesh view large_scan.las --background light

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inspect

Show metadata about a point cloud file without loading it fully into a mesh pipeline.

scan2mesh inspect <input>

For E57 files, prints a table with per-scan point count, available fields (x/y/z, intensity, color), and bounding box. For other formats, shows basic point cloud statistics (count, bounds, has-colors, has-normals).

Examples

scan2mesh inspect examples/pump.e57
scan2mesh inspect cloud.ply

Use this first on unfamiliar E57 files so you know what --scans selectors to pass to convert or split.

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split

Split an E57 file into individual per-scan files.

scan2mesh split <input.e57> <output_dir>

Each scan is written as a separate point cloud. Useful when a multi-scan E57 needs to be processed scan-by-scan or fed to a tool that can't read E57.

Options

Flag	Description	Default
--format {ply,pcd,las}	Output format for each scan file.	ply
--scans "0,2,3"	Only export these scan indices.	All

Examples

# Split every scan into PLY files
scan2mesh split examples/pump.e57 ./pump_scans/

# Only scans 0, 2, 3 — as PCD
scan2mesh split building.e57 ./scans/ --format pcd --scans 0,2,3

Currently only E57 input is supported (no other format stores independent scans).

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Pipeline (convert)

1. Read — format-specific reader → unified point cloud
2. Estimate spacing — k-NN sample to size voxels and reconstruction radii from the scene's native resolution
3. Downsample — voxel-grid (skippable in some presets)
4. Outlier removal — radius-based when spacing is known, statistical otherwise (skippable via --no-outlier-removal)
5. Normal estimation — fast viewpoint flip (BPA) or consistent MST orientation (Poisson)
6. Surface reconstruction — Poisson or Ball Pivoting
7. Post-process — decimation (face-count or deviation) + vertex color transfer
8. Export — OBJ / GLB / glTF / STL

Tips

• Huge clouds + precision/high: the pipeline auto-bumps voxel_size if the post-downsample count would exceed the Ball Pivoting practical limit (~1.5M points). Watch for the WARNING: Ball Pivoting input ... bumping voxel_size line in -v mode.
• Holes with BPA? Extend radii: --bpa-radii 1,2,4,8, or switch to --mode visualization to fill gaps with Poisson.
• Ctrl+C works at any stage — blocking calls run in daemon threads.

Development

pip install -e ".[dev]"
pytest tests/

License

MIT — see LICENSE.