6.1. Point Clouds

IQcad can import, display, and export large point cloud datasets (hundreds of millions of points). Point cloud data is stored in an octree spatial index for efficient LOD (Level of Detail) rendering.

6.1.1. Importing a Point Cloud

Use Point Cloud › Import Point Cloud or the IMPORTPOINTCLOUD command.

Supported import formats:

Format

Description

LAS

ASPRS LAS 1.0–1.4. XYZ, intensity, classification, RGB, return number.

LAZ

LASzip-compressed LAS. Requires laszip.dll (Windows) or liblaszip.so (Linux) next to the executable.

XYZ / CSV / TXT

Delimited text: X Y Z [R G B] [Intensity] [Classification].

PTS / PTX

Leica interchange formats. Header with point count, then X Y Z I R G B.

PLY

Stanford PLY (ASCII and binary little-endian). Vertex x y z [red green blue].

E57

ASTM E2807 / libE57Format. Multi-scan files with XYZ, RGB and intensity. Requires the libE57CWrapper dynamic library next to the executable; if absent the format is silently disabled and does not appear in the import dialog.

After import, an .iqpc octree cache file is created next to the source file. Subsequent opens load from cache in seconds instead of re-processing.

6.1.2. Attaching a Cache

Use Point Cloud › Attach Point Cloud Cache or ATTACHPOINTCLOUD to load an existing .iqpc file directly, without the original source file.

6.1.3. Exporting a Point Cloud

Use Point Cloud › Export Point Cloud or EXPORTPOINTCLOUD.

Supported export formats: LAS, LAZ, XYZ, PTS, PLY, E57. The export runs in a background thread with a progress bar and cancel support.

E57 export emits a single scan with XYZ plus RGB and intensity (when the source cloud carries them). Intensity is normalised to the 0..1 Double range required by the E57 spec. As with import, E57 export needs the libE57CWrapper library at runtime.

6.1.4. Elevation Clipping

Use Point Cloud › Elevation Clip or the PCCLIP command to filter the visible points by elevation (Z) range.

  • PCCLIP 80 160 — show only points with Z between 80 and 160.

  • PCCLIP OFF — disable clipping, show all points.

  • PCCLIP — display current clip state and cloud Z range.

This is useful for viewing specific floor levels in building scans, isolating terrain from vegetation, or inspecting horizontal cross-sections.

The clip range is saved with the drawing (IQZ file).

6.1.5. Point Cloud Display

Six colour modes are available (set via Object Inspector):

  • True Colour — uses RGB stored in each point.

  • By Elevation — maps Z to a blue→red colour ramp.

  • By Intensity — maps sensor return intensity to greyscale.

  • By Classification — LAS classification codes with standard colours.

  • Single Colour — flat colour for all points.

  • By Return Number — first/second/third returns in red/green/blue.

Point size and attenuation are configurable. The adaptive LOD system automatically reduces detail at zoom-out to maintain interactive frame rates (default 5 million point budget).

For a live Z readout of the nearest point under the cursor as you move the mouse — the point cloud counterpart of the surface Elevation Tracker — see the Elevation Tracker section (PCELEVTRACK command) in TIN Surfaces.

6.1.6. Prospector Integration

The Civil Toolspace shows a Point Clouds node. Right-click on an individual point cloud for:

  • Show / Hide — toggle visibility.

  • Zoom To — fit the viewport to the point cloud bounds.

  • Delete — remove the point cloud from the drawing (with confirmation, undoable via Ctrl+Z).