How to Interpret a 3D Scan: A Practical Guide for Clients

3D scanning has transformed the way surveyors capture and document existing conditions. By creating highly accurate “digital twins” of buildings, objects, and environments, scanning technology allows teams to visualise real-world structures with exceptional precision—reducing rework, avoiding errors, and speeding up project delivery.

To make the most of your scan, it’s important to understand what the data represents and how to evaluate its accuracy. This guide walks you through the key elements of a 3D scan and how to interpret the information with confidence.

Understanding the Types of 3D Data

Producing a 3D scan is only part of the process. Making the data useful, understandable, and valuable for clients is equally important. Here are the formats you’re most likely to encounter and what each one means.

Laser scanning, photogrammetry, and kinematic LiDAR all generate point clouds—millions of precise points that map the geometry of a surface or space. Before cleaning or processing, this data may look “noisy” or incomplete, but it holds the highest level of detail.

Common file types: .E57, .RCP, .RCS, .LASBest for:

• Accurate as-built conditions
• Clash detection
• Integration into CAD/BIM workflows

2. Processed Meshes or 3D Models

A mesh connects the points in the cloud, creating visible surfaces and shapes. Meshes are far easier to understand visually and are ideal for presentations or design reviews.

Common file types: .OBJ, .STLBest for:

• Concept visualisations
• Inspection and comparison overlays
• Easy viewing for non-technical teams

3. CAD or BIM Deliverables

Most clients ultimately receive structured, editable models created from the scan. These allow architects, engineers, and contractors to work directly with the captured information.

Common file types: .DWG, .RVTBest for:

• Design development
• Fabrication and manufacturing
• Renovation or refurbishment planning
• Multi-discipline coordination

4. Visual Reports and Walkthroughs

Many providers also supply viewer-friendly outputs such as orthophotos, deviation maps, PDFs, or navigable 3D walkthroughs. These help you explore the data interactively and understand the real-world spatial context.

What to Look for in Your 3D Scan

Interpreting a scan is all about understanding its quality, completeness, and reliability. As you review your data, keep the following points in mind.

Ask these key questions:

• What is the stated accuracy (e.g., ±2 mm, ±5 mm)?
• Were control points or benchmarks used to align the scan?

Scans tied to a coordinate system ensure consistent measurement and reliable documentation.

Coverage and Completeness

Check for:

• Shadows or blind spots
• Missing detail in tight corners
• Gaps caused by reflective or transparent surfaces

A professional scanning report should highlight these limitations so you know exactly what is and isn’t captured.

Registration and Alignment

A full 3D scan is created from multiple scan positions stitched together. When reviewing, zoom in to check for:

• Misalignment
• Duplicated edges
• Warping between stations

Even slight registration errors can affect measurements.

Noise and Outliers

Clean data is important. Too many stray points can distort accuracy, but over-cleaning can remove useful detail. The goal is a balanced, well-filtered dataset.

Deviation and Comparison Maps

Deviation maps are colour-coded visualisations that show how a surface differs from design intent.

• Green: within tolerance
• Red/Blue: areas outside tolerance

These maps are invaluable for identifying construction movement, deflection, or installation variances early.

How to Explore and Visualise Your Scan

Understanding your scan is easier when using the right tools and visual methods.

3D Walkthroughs and 360° Navigation

Walkthroughs let you “step inside” the data, moving through spaces as if on site. Tools often include:

• On-screen measurements
• Markers or hotspots
• Notes on critical features or routes

Cross-Sections and Slices

Horizontal and vertical slices help you see internal relationships, structural alignments, or level changes that may not be visible from the outside.

Design Overlays

Overlaying your BIM model onto the scan reveals clashes or deviations between design and reality. Transparency tools and section views help identify where adjustments are needed.

Colour Mapping and Heatmaps

Heatmaps show deformation, bowing, settlement, or displacement across surfaces—especially useful for structural inspections or retrofit planning.

Turning Data Into Insight

A high-quality 3D scan can reveal misalignments, structural concerns, or installation issues long before they become costly problems. The ability to identify and address these early is the foundation of effective decision-making.

At South West Surveys, we do more than deliver accurate data—we guide you through it. Whether you need help interpreting your scan, navigating your deliverables, or integrating the data into your workflow, our team is here to support you every step of the way.

Ready to get more value from your next project? Book your 3D scan or speak to one of our specialists today.