3D Laser Scanning Glossary

Linking the terms in a proposal to what they mean on site

Definitions for the terms in a scanning proposal: registration, point density, LOA, georeferencing, and the file types you will receive.

Registration, Targets, and Tolerances

Where individual scans meet in one cloud

How individual scan positions are stitched into one cloud, and why registration error is the hidden cost of a cheap scan.

LiDAR, SLAM, and Terrestrial Scanning

Spanning three capture methods and three accuracy classes

Three capture methods, three accuracy classes. Know which one a vendor is quoting before you compare prices.

Point Density and Scan Resolution

Connecting scan resolution to the deliverable

Higher density means more detail and larger files. The right setting depends on the deliverable, not the scanner.

Every Term in Context

Guides that carry each term from site visit to point cloud

The guides hub walks through each term in context, from first site visit to delivered point cloud.

3D Laser Scanning Glossary

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3D Laser Scanning Terms: A Field-Capture Glossary

This glossary focuses on the vocabulary of reality capture — the terms surveyors, scan technicians, and reviewers use before a single drawing or model is produced. Understanding how a scan is captured, aligned, and quality-checked helps architects, contractors, and owners judge whether the data behind a deliverable is trustworthy. Below are the field-capture concepts we reference most often on Pittsburgh and Western PA projects.

Point Cloud

A point cloud is the primary output of a laser scan: millions to billions of individual measured points, each carrying XYZ coordinates and usually a color or intensity value. The cloud is the raw digital record of a space and the source of truth every downstream CAD drawing or BIM model is traced from.

Registration

Registration is the process of stitching multiple scan positions into one coherent coordinate system so overlapping data lines up perfectly. Poor registration introduces ‘ghosting’ or doubled surfaces; tight registration keeps the whole dataset within a few millimeters end to end.

Core field-capture terms (part 1)The vocabulary used before any drawing is produced
  • Point CloudMillions to billions of measured points, each carrying XYZ coordinates and usually color or intensity. The raw digital record every drawing and model is traced from.
  • RegistrationStitching multiple scan positions into one coordinate system so overlapping data lines up. Poor registration shows as ghosting or doubled surfaces.
  • Scan Resolution and DensityHow closely spaced the points are, given as spacing at a distance — for example 3 mm at 10 m. Higher density catches conduit and moldings but grows file size.
  • Occlusion and Line of SightA scanner only records what it can see. Anything hidden behind ductwork, equipment or furniture leaves a shadow of missing data.
  • Intensity and NoiseIntensity is the strength of the returned pulse and helps read materials and signage. Noise is stray points from glass, wet surfaces or movement, filtered in processing.
CAD Construct LLC3D Laser Scanning & Reality CapturePittsburgh, PAcadconstructllc.com

Target-Based vs. Target-Less Registration

Target-based registration uses physical checkerboards or spheres placed in the scene as common reference points, favored where accuracy must be provable. Target-less (cloud-to-cloud) registration aligns overlapping geometry itself, which is faster and less intrusive on occupied sites.

Scan Resolution & Density

Scan resolution, or density, is how closely spaced the measured points are, usually expressed as point spacing at a set distance (for example, 3 mm at 10 m). Higher density captures fine detail like conduit and moldings but produces larger files and longer processing, so resolution is matched to the deliverable.

Core field-capture terms (part 2)Alignment, control and what actually gets delivered
  • Target-Based vs. Target-LessTwo ways to register a project: physical checkerboards and spheres placed in the scene, or aligning the overlapping geometry itself.
  • Georeferencing and ControlTying the scan to real-world survey coordinates using a control network or GPS, so the data aligns with site plans, civil drawings and adjacent phases.
  • Deliverable FormatsE57 and PTS for broad interoperability, RCP and RCS for Autodesk ReCap and Revit, LAS and LAZ for survey and GIS workflows.
  • Coverage and OverlapHow much of a space the scan captures, and how much data adjacent positions share. Healthy overlap runs 30 to 40 percent.
CAD Construct LLC3D Laser Scanning & Reality CapturePittsburgh, PAcadconstructllc.com

Occlusion & Line of Sight

A scanner only records what it can see. Anything hidden behind ductwork, equipment, or furniture becomes an occlusion — a shadow of missing data. Planning enough scan positions to eliminate critical occlusions is the difference between a complete model and one full of guesswork.

Intensity & Noise

Intensity is the strength of the returned laser pulse, which helps distinguish materials and read signage in the cloud. Noise refers to stray or low-confidence points caused by reflective glass, wet surfaces, or moving objects, and is filtered during processing.

How the terms connectEach term marks one checkpoint in the capture sequence
  1. CaptureThe scanner records millions to billions of points from each position.
  2. RegisterOverlapping positions are stitched into one coordinate system, so the data lines up.
  3. Control and clean-upGeoreferencing ties the cloud to real site coordinates, while noise is filtered out.
  4. DeliverThe registered cloud is exported to the format each downstream tool needs.
Ask about setups, point spacing, registration method and site control — the answers decide whether drawings hold up when trades build against them.
CAD Construct LLC3D Laser Scanning & Reality CapturePittsburgh, PAcadconstructllc.com

Georeferencing & Control

Georeferencing means tying the scan to real-world survey coordinates using a control network or GPS so the dataset aligns with site plans, civil drawings, and adjacent phases. Georeferencing matters most on large sites, additions, and multi-trade coordination.

Numbers behind the termsThe figures that decide whether a deliverable holds up
  • 3 mmExample point spacing at 10 m — density is matched to the deliverable, not simply maximized
  • 30–40%Healthy overlap between adjacent positions, giving registration common geometry to lock onto
  • BillionsMeasured points a project cloud can carry, each with XYZ plus color or intensity
  • 6Export formats in common use — E57, PTS, RCP, RCS, LAS and LAZ
Tight registration keeps the whole dataset within a few millimeters end to end.
CAD Construct LLC3D Laser Scanning & Reality CapturePittsburgh, PAcadconstructllc.com

Deliverable Formats

Registered clouds are exported to formats suited to each tool: E57 and PTS for broad interoperability, RCP/RCS for Autodesk Recap and Revit, and LAS/LAZ for survey and GIS workflows. Choosing the right format up front avoids costly reprocessing.

Coverage & Overlap

Coverage and overlap describe the share of a space captured by the scan and the amount of shared data between adjacent positions. Healthy overlap (typically 30–40%) gives registration enough common geometry to lock onto, while thorough coverage ensures no wall, ceiling, or riser is left undocumented.

Commonly confused: two ways to registerTarget-based vs. target-less (cloud-to-cloud)
Target-based registration
  • Checkerboards or spheres placed in the scene
  • Reference points are physical and provable
  • Favored where accuracy must be demonstrated
  • Adds setup time on site
Target-less (cloud-to-cloud)
  • Aligns the overlapping geometry itself
  • No targets to place, protect or remove
  • Faster and less intrusive on occupied sites
  • Depends on healthy 30–40% overlap
  • Suits live, furnished or busy interiors
CAD Construct LLC3D Laser Scanning & Reality CapturePittsburgh, PAcadconstructllc.com

Why These Terms Matter

When you request a quote or review a scan deliverable, this vocabulary lets you ask sharper questions: How many setups? What point spacing? Target-based or cloud-to-cloud? Is it georeferenced to our site control? The answers determine whether the resulting drawings and models will hold up when trades build against them. If you would like any term explained in the context of your building, our team is glad to walk through it before capture begins.

Software and equipment mentioned on this page
We aren't affiliated with or sponsored by any of the companies listed here, but we're always looking to work closely with the companies whose tools we recommend.
  • Autodesk ReCap Pro logoAutodesk ReCap Pro
  • Autodesk Revit logo