Is my IFC file uploaded anywhere?

No. Files are parsed entirely in your browser via web-ifc, a WebAssembly build of the open-source IFC parser. Nothing leaves your machine. The app works completely offline once loaded.

Can I use it with confidential models under NDA?

Yes. Because all processing happens in your browser and no data is ever transmitted to any server, you can safely use it with confidential project models under NDA. There is no service agreement to review with your client — no data changes hands.

Can I share the validation results with my team or client?

Yes. After running validation, click Share Report to copy a link that encodes the full Health Score and issue list directly in the URL — no file upload, no server, no account required. You can also export results as JSON, CSV, or a Validation Certificate. The IFC file itself never leaves your browser.

Yes, fully. IFC Viewer Online works on any modern browser — Chrome, Edge, Firefox, and Safari on both Mac and Windows. No plugin, no installation, no operating system restriction.

What happens if my IFC file is very large?

The app handles files up to 2 GB. Performance depends on your device — files under 200 MB load well on most modern hardware. Once parsed, geometry is cached in OPFS so every subsequent load of the same file is instant, even offline.

How does the validation work?

The validator runs 44 built-in rules in a background Web Worker so the UI stays responsive. Rules cover GUID duplicates, spatial hierarchy, orphan elements, naming conventions, missing type assignments, ISO 19650 property sets, LOD completeness, clash detection, proxy overuse, coordinate offset, storey-elevation integrity, unit consistency, and more. You can also run a buildingSMART IDS specification against the model. Every model receives a Health Score from 0 to 100. Results stream in as each rule completes.

Can I fix errors and re-export a corrected IFC?

Yes. All edits (GUID fixes, renames, property value changes) are held as non-destructive diffs with full undo/redo. Clicking Export IFC applies all diffs to the original binary in a Web Worker and downloads the corrected file — no server involved.

What IFC versions are supported?

IFC2x3, IFC4, IFC4x1, and IFC4x3. The viewer uses the open-source web-ifc parser — the same engine used by most modern BIM tools and @thatopen/components. Outdated schemas are automatically flagged by the validator.

What measurement tools are available?

You can measure lengths between any two points, areas of surfaces, volumes of enclosed elements, and individual edge lengths — all directly in the 3D viewport. Measurements persist as labelled annotations and can be exported alongside your model.

Can I load multiple IFC files at once?

Yes. Load as many IFC files as your device memory allows. Each model has independent visibility, transforms, validation, quantity takeoff, and export. Use the Scene panel to manage, reorder, or remove models at any time.

Does it work offline?

Yes, once the page is loaded. The WebAssembly parser and WebGL renderer run entirely in the browser. Parsed geometry is cached in OPFS so repeat loads are instant even without a network connection.

What are the file size limits?

There is no enforced limit — performance depends on your device. Files up to ~200 MB typically load well on modern hardware. The OPFS geometry cache means you only pay the parse cost once per file.

Is it free? Can I use it for commercial projects?

Yes, completely free. The source code is MIT-licensed. You can use the live app or fork the repository for your own projects, including commercial ones.

Is the wall-condition patch an automated diagnosis?

No. It is a pulsing synthetic point cluster for demonstrating localization and communication. A real diagnosis needs calibrated sensing, a defined measurement method and expert review.

Why is the tunnel cloud denser than the other examples?

Linear infrastructure has repeated services and long surfaces that need enough samples to remain legible while moving. The demo still caps capacity at about 51,000 points and reuses one GPU buffer.

Can this architecture work with a mobile mapping trolley?

Yes, if an edge adapter supplies normalized frames, timestamps and a calibrated pose in the IFC/site coordinate system. The browser should receive bounded display data rather than raw sensor bandwidth.

Back to the BIM & IFC blog

Digital Twins · 2026-08-27 · 8 min

Tunnel Inspection Digital Twin: IFC + Mobile LiDAR Replay

Move an inspection trolley through dense services, visualize its scan fan and localize a changing wall-condition cluster in the IFC corridor.

Actual IFC Viewer Online utility tunnel with dense service points, moving inspection trolley, cyan scan fan and localized red wall-condition returns

Linear infrastructure is difficult to explain with isolated photos. A defect image may show moisture or deformation, but not which wall segment, service crossing or chainage the evidence belongs to. A mobile point-cloud replay preserves the geometry around the observation while IFC keeps the corridor assets identifiable.

The demo combines dense envelope and service returns with a moving inspection trolley, a cyan scan fan and a localized red wall-condition cluster. Everything temporal is synthetic and clearly labelled. It exists to exercise the viewer and give exhibitors a repeatable story without claiming a live device connection.

Inspect the utility tunnel live

Utility tunnel — IFC + mobile LiDAR

Interactive 22-second replay with roughly 49,000 visible points, a moving trolley, scan fan and localized wall-condition cluster.

Actual product interface showing the mobile LiDAR trolley and scan fan inside the matching IFC utility tunnel — Inspection replay is running — follow the trolley

A useful inspection scene answers three questions

Where is the observation in the asset coordinate system?
What surrounding geometry and IFC objects give it context?
What is measured evidence, what is an algorithmic result and what is an annotation?

Those questions are why the replay does not replace points with a rendered MP4. Video is excellent for texture and narrative, but a point frame still lets the user change viewpoint, query attributes and compare the observation with the model.

Download the tunnel pair

Use the utility tunnel IFC4 model and the representative mobile LiDAR PLY to test alignment and point styling. Start the live example or export MCAP for movement.

Browser responsibility	Edge responsibility	Project responsibility
Validate packet, bound memory, render, inspect and report status	Synchronize pose, filter/voxelize, normalize attributes and compress	Define asset frame, control, tolerances, retention and review workflow
Show source truth and uncertainty	Drop corrupt or stale frames	Decide what creates an issue or work order

Performance in a long, repetitive corridor

The static service catalogue is created once. Only the trolley, rings, fan and condition patch are rewritten per frame, below a fixed 51,134-point capacity. The viewer draws within its global point budget and can pause, seek or jump to the latest frame without accumulating historical geometry.

Tunnel Inspection Digital Twin: IFC + Mobile LiDAR Replay