RevitSync

Real-time bidirectional sync between Autodesk Revit and a web-based 3D viewer.

Demo Video

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Features

Revit → Web

• Geometry Export: Extract bounding boxes from 13 Revit categories
• Auto-Sync: DocumentChanged event triggers automatic export
• Selection Sync: Revit selection highlighted in web viewer (cyan)
• Properties Panel: View Family, Type, Level, Area, Volume in browser
• Category Colors: Each category has distinct color for visualization

Web → Revit

• Click-to-Place: Add boxes in browser, appear as DirectShapes in Revit
• Drag-to-Move: Reposition web-created elements with transform handles
• Delete Elements: Remove web-created elements from both sides
• Selection Sync: Click element in web, highlights and zooms in Revit

Categories Exported

Walls, Roofs, Floors, Structural Columns, Structural Framing, Structural Foundation, Windows, Doors, Curtain Wall Panels, Curtain Wall Mullions, Stairs, Ramps, Generic Model

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Tech Stack

Component	Technology
Revit Add-in	C# / .NET Framework 4.8 / Revit API 2024+
Backend API	ASP.NET Core 9, In-memory storage, REST
Frontend	React 18, TypeScript, Three.js (React Three Fiber), TanStack Query, TailwindCSS

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Architecture

┌─────────────────────────────────────────────────────────────────────────────┐
│                              REVIT ADD-IN                                    │
│  ┌──────────────┐  ┌──────────────┐  ┌──────────────┐  ┌──────────────┐    │
│  │    App.cs    │  │  Geometry    │  │   Command    │  │  AutoExport  │    │
│  │  (Startup)   │  │  Exporter    │  │   Poller     │  │   Handler    │    │
│  └──────────────┘  └──────────────┘  └──────────────┘  └──────────────┘    │
│         │                 │                 │                 │             │
│         └─────── DocumentChanged / Idling ──┴──── ExternalEvent ────────────┘
└─────────────────────────────────────────────────────────────────────────────┘
                     │ POST /geometry              │ GET /commands/next
                     ▼                             ▲
┌─────────────────────────────────────────────────────────────────────────────┐
│                           ASP.NET CORE BACKEND                               │
│  ┌────────────────────────────────┐    ┌────────────────────────────────┐  │
│  │     GeometryController         │    │     CommandsController         │  │
│  │  POST /api/geometry            │    │  POST /api/commands            │  │
│  │  GET  /api/geometry/latest     │    │  GET  /api/commands/next       │  │
│  └────────────────────────────────┘    └────────────────────────────────┘  │
│           ConcurrentDictionary                    ConcurrentQueue           │
└─────────────────────────────────────────────────────────────────────────────┘
                     │ GET /geometry/latest        │ POST /commands
                     ▼                             ▲
┌─────────────────────────────────────────────────────────────────────────────┐
│                          REACT FRONTEND                                      │
│  ┌────────────────────────────────┐    ┌────────────────────────────────┐  │
│  │    useLatestGeometry           │    │    useEnqueueCommand           │  │
│  │    (polls every 2s)            │    │    (mutation hook)             │  │
│  └────────────────────────────────┘    └────────────────────────────────┘  │
│  ┌──────────────────────────────────────────────────────────────────────┐  │
│  │                    LiveGeometryView (Three.js)                        │  │
│  │   3D Canvas  │  Properties Panel  │  Control Panel  │  Category Legend│  │
│  └──────────────────────────────────────────────────────────────────────┘  │
└─────────────────────────────────────────────────────────────────────────────┘

Data Flow

• Revit → Web: Geometry exported via POST, frontend polls GET every 2s
• Web → Revit: Commands queued via POST, add-in polls GET every 500ms
• Latency: ~500ms-2s

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Prerequisites

• Autodesk Revit 2024+ (tested with 2024, 2025, 2026)
• .NET 9 SDK (for backend)
• Node.js 18+ (for frontend)
• Visual Studio 2022 (for Revit add-in)

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Quick Start

1. Backend

cd backend/RevitSync.Api
dotnet run

Runs on http://localhost:5245 | Swagger UI at http://localhost:5245/swagger

2. Frontend

cd frontend/revit-sync-frontend
npm install
npm run dev

Runs on http://localhost:5173

3. Revit Add-in

1. Open revit-addin/RevitSync.Addin/RevitSync.Addin.sln in Visual Studio
2. Build the solution (post-build copies DLL automatically)
3. Create a .addin manifest file (see below)
4. Restart Revit

Addin Manifest

Create RevitSync.addin in %APPDATA%\Autodesk\Revit\Addins\2026\:

<?xml version="1.0" encoding="utf-8"?>
<RevitAddIns>
  <AddIn Type="Application">
    <Name>RevitSync</Name>
    <Assembly>RevitSync.Addin.dll</Assembly>
    <FullClassName>RevitSync.Addin.App</FullClassName>
    <AddInId>7AF9D8DB-6CEA-4E88-98FE-B2ED1BF112C3</AddInId>
    <VendorId>RevitSync</VendorId>
  </AddIn>
</RevitAddIns>

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Usage

1. Open Revit with a project containing walls, floors, roofs, etc.
2. Click "Export Geometry" in the RevitSync ribbon panel
3. Open browser at http://localhost:5173
4. Explore the model - orbit, pan, zoom the 3D view
5. Click elements to see properties in the side panel
6. Click "Select in Revit" to highlight and zoom in Revit
7. Select in Revit - element highlights cyan in web viewer
8. Place boxes - click "Click to Place" → click on ground
9. Move boxes - select web-created box → drag transform arrows
10. Delete boxes - select → click Delete button

Changes sync automatically via DocumentChanged event (no manual re-export needed).

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API Endpoints

Endpoint	Method	Description
/api/geometry	POST	Ingest geometry snapshot from Revit
/api/geometry/latest	GET	Get latest snapshot (supports ETag caching)
/api/commands	POST	Queue command for Revit
/api/commands/next	GET	Dequeue next command (polled by Revit)

Command Types

Type	Description
ADD_BOXES	Create DirectShape boxes in Revit
DELETE_ELEMENTS	Delete elements by ID
MOVE_ELEMENT	Move element to new position
SELECT_ELEMENTS	Select and zoom to elements

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License

MIT