Showing a client a building that doesn't yet exist is traditionally the task of render farms and video presentations. AR changes the format: the architect arrives at the site, points a tablet at the ground, and the 3D model of the building appears precisely in its place at 1:1 or 1:100 scale. We implement such projects turnkey — from converting BIM models to publishing in app stores. The client walks around the building, looks inside, changes facade materials. This is not a replacement for renders — it's another tool for a different conversation: live, interactive, convincing.
Two Modes: Site-Scale and Table-Scale
Site-scale (plot scale, 1:1). The building is placed on the real site using ARKit Geo Tracking or GPS+compass. The user physically walks around the virtual structure. Requires a device with A12+ and a supported city for Geo Tracking. For suburban plots — only GPS with 3-8 meter accuracy.
Table-scale (model scale, 1:100 and smaller). The model of a block or building is placed on a table or floor like a maquette. Plane detection + placement. Suitable for office presentations, exhibition stands. Simpler to implement, works on all ARKit/ARCore devices.
Often both modes are used with a switch: "view as maquette" / "enter the building".
| Parameter | Site-scale | Table-scale |
|---|---|---|
| Scale | 1:1 | 1:100 and smaller |
| Positioning technology | ARKit Geo Tracking / GPS | Plane detection |
| Device requirements | A12+, iOS 14+ (ARKit 5) | Any ARKit/ARCore |
| Ideal use case | Presentation on site | Office demos, exhibitions |
What to Choose: Site-Scale or Table-Scale?
The choice depends on the scenario. If you plan to show the building on the actual plot with landscape reference — definitely site-scale. For demonstration in a meeting room or at a booth, table-scale is more convenient. We help clients determine the optimal mode and, if needed, implement both with a single gesture switch.
Working with Architectural BIM Models
Architects work in Revit, ArchiCAD, Rhino. Direct import of these formats into ARKit/ARCore is impossible — conversion is needed:
- Revit → FBX/OBJ via export or Autodesk Forge API → GLTF via gltf-pipeline or Blender
- ArchiCAD → IFC → conversion via IfcOpenShell → GLTF
- Rhino → OBJ/FBX → GLTF
The main problem with BIM models: Level of Detail (LOD) is too high for real time. A residential complex model in Revit LOD 300 — 10-50 million polygons. For AR, you need 200k-2M maximum. Retopology and LOD are mandatory steps, often taking more time than the AR development itself. AR visualization reduces approval time by 3-5 times compared to traditional renders.
Optimization tools: Simplygon (automatic retopology, cloud service), Blender Decimate Modifier (free, manual control), Reality Composer Pro (Xcode 15+) for final packaging into .reality with baked textures.
| Tool | Type | Cost |
|---|---|---|
| Simplygon | Cloud | Paid, subscription |
| Blender Decimate | Local | Free |
| Reality Composer Pro | Local (macOS) | Free (Xcode) |
How to Convert a BIM Model to AR?
The process includes three steps: export from the CAD system to an intermediate format (FBX/OBJ/IFC), conversion to GLTF, and polygon optimization to an AR-acceptable count. At this stage, textures are also baked and LOD levels are set. Without optimization, even powerful devices cannot smoothly display a complex model.
Interactivity: Floors, Apartments, Materials
For presenting a residential complex to a client, more than a static model is needed:
- Floor selection. We split the model into separate ModelEntity objects by floor. Tap gesture on a floor — highlight selected, others reduce opacity to 0.3. In RealityKit — ModelComponent.materials with SimpleMaterial(color: .yellow.withAlphaComponent(0.5)).
- Apartment interior view. Separate scene with the apartment interior, switching via ARView.scene.anchors.removeAll() + load new scene. Or — transition to VR mode (SceneKit + AVPlayer + 360° panorama).
- Facade material switching. Brick / plaster / glass — swap texture on entity.model?.materials. Textures in .ktx2 format for fast loading.
Streaming 3D Content
A full residential complex model in GLB — 50-200 MB. Cannot be embedded in the app. Options:
- Progressive loading via Reality Composer Pro: .reality files support streaming — RealityKit loads LOD as the camera approaches.
- Babylon.js + WebXR in WKWebView: for web-based approach with streaming via GLTF extensions (MSFT_lod, KHR_materials_variants).
- Cesium for Mobile: if the model is geo-referenced and needs 3D Tiles streaming.
Collaborative Viewing (Multiplayer AR)
Several people see the same model in the same space — via MultipeerConnectivity + ARKit collaborative session. ARSession.getCurrentWorldMap() → send via Multipeer → ARWorldTrackingConfiguration.initialWorldMap on other devices. All participants see the same scene with shared anchors.
Works up to ~30 meters via Wi-Fi/Bluetooth. For large sites — server-side position synchronization via WebSocket.
What's Included in the Work
- Conversion of BIM model to optimized GLTF with baked textures
- Development of AR app for iOS and Android (Swift/Kotlin, RealityKit/ARCore)
- Configuration of interactivity: floor selection, apartment views, material switching
- Implementation of site-scale and/or table-scale modes
- Setup of collaborative viewing (optional)
- Testing on target devices, publication in App Store and Google Play
- Training of client staff on using the app
- Technical support for one month after launch
Experience and Expertise
We have been developing AR solutions for over 5 years. Our portfolio includes more than 10 projects for architectural firms and developers. We guarantee quality and adherence to deadlines. Assess your project for free — write to us.
Timeframes
Table-scale visualization with one model without interactivity — 2-3 weeks (including model conversion). With interactive floors, material switching, site-scale via Geo Tracking — 6-10 weeks. Multiplayer AR — plus 2-3 weeks. The cost is calculated individually.