BIM to web 3D walkthrough: how a Revit or ArchiCAD model becomes interactive 3D in the browser

Why a BIM model is not automatically browser-ready

A BIM model holds everything a project needs: structure, wall build-ups, services, element families and parameters. For a buyer walking through an apartment, most of that data is invisible, and for a browser it is dead weight. A web walkthrough has to run with no installation, even on an average laptop or phone, so the geometry is converted and simplified.

The good news is that a well-kept BIM model is an excellent starting point. Correct floor levels, accurate dimensions and consistent openings save a great deal of manual work. The bad news is that every surface inconsistency in the model will also show in the final view.

What the model must contain before you hand it over

Start with a closed, clean architectural shell. A walkthrough shows everything the camera sees, so gaps between walls and ceilings, doubled walls or missing floors are noticed immediately. Check the units and the origin of the coordinate system too: a model in millimetres instead of metres produces the wrong scale and problems with camera height.

You can safely leave out of the export anything that will not be visible in the final view: services, reinforcement, junction details and hidden layers. The fewer unnecessary elements that go into the export, the fewer corrections follow.

• Finished walls, floors, ceilings, roof and façade with no holes or overlaps
• Windows and doors modelled as real openings, with glazing and frames at the right sizes
• Stairs, railings, balconies and parapets at their actual dimensions
• Named rooms and a consistent apartment code, if you want unit selection in the view
• Materials assigned by surface (floors, walls, façade), not a single default material
• Terrain, neighbouring buildings and a basic external layout for context

Revit model to interactive 3D: from export to optimisation

The route from Revit or ArchiCAD usually runs through an export to a 3D processing format (for example FBX, OBJ or glTF) or through IFC. The exported file is not yet the finished view. In an intermediate tool the geometry is cleaned, elements are merged, hidden surfaces are removed and the polygon count is reduced wherever it does not affect appearance.

For the web, the model is then prepared in a lightweight format, often glTF or GLB, with compressed geometry and textures. The goal is twofold: a fast first load and smooth movement through the space. Simplified collision geometry is also used, so the camera does not catch on furniture or railings.

A typical workflow looks like this:

• Review the model and agree what is visible and what is not
• Clean-up: remove hidden elements, repair faces and normals
• Simplify the geometry and prepare collision surfaces
• Assign materials, textures and lighting
• Test across several browsers and on mobile devices

IFC viewer in the browser: when IFC is the right choice

IFC is an open, neutral format that comes in handy when teams use different software or when the source file is not available. Besides geometry it carries data such as rooms, areas and element tags. That is useful because you can build floor or apartment selection from it.

Care is needed with IFC for visualisation, though. Materials are often lost or simplified on export, curved surfaces can be triangulated differently, and the result depends on export settings and the format version. It therefore makes sense to use IFC as a source of data and structure, and to supplement the look with your own material work.

If you have the original model in Revit or ArchiCAD, the most reliable approach is to combine both: IFC for room and unit data, and a direct geometry export for a more faithful appearance.

Materials, light and interactivity

The look of a walkthrough is set by materials and light, not by geometry alone. For the web, lighting is often precalculated and baked into the textures, which allows real-time display without straining the device. Textures must be sharp enough for close viewing but no larger than necessary, because oversized ones lengthen loading.

Interactivity is added on top of the geometry: floor selection, unit selection, display of area or orientation, movement between rooms. Room data can be drawn from BIM, while sales status and prices usually come from the developer’s system. ARHIX builds such views as a free-roam 3D walkthrough in the browser, which you can try on the public demo of a sample house.

Common errors when moving from BIM to a web walkthrough

Most problems are not technically complicated, but they surface late and force a return to the source model. If you know them in advance, you can eliminate them at the modelling stage.

One approach is especially common: “export everything”. The file is then large, slow and full of elements nobody will ever see.

• Overlapping or duplicated surfaces that cause texture flicker
• Flipped normals that make walls invisible from some sides
• A model with no openings in walls, or with glazing modelled as solid bodies
• Over-detailed elements such as bolts, reinforcement or densely meshed curved surfaces
• A single default material across the whole model, so floors, walls and façade cannot be told apart
• Wrong units or origin, leaving the camera too low, too high or far from the building
• Missing surroundings, which make the building look like an object floating in a void

What you can do today

Open your current model and check it against the list in the second section: closed shell, real openings, tidy materials, consistent apartment codes. This review alone usually uncovers more issues than you would expect.

If you want to see what the finished result looks like, try the public demo and judge which level of detail makes sense for your project. To assess how suitable your own model is, you can prepare an IFC export and review it together before you decide to commission anything.