Open Construction Modeler

An open-source, construction-first modeling engine built for VDC coordinators, trade contractors, and construction technology teams.

Built because existing tools like Revit and Navisworks were designed for architects — not for the people who actually build things.

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What This Is

A two-part ecosystem:

Part 1 — Desktop Modeling Engine (this repo)
A fast, construction-centric 3D modeling engine with first-class support for trade coordination, assembly modeling, clash detection, and construction sequencing.

Part 2 — Collaboration Platform (coming soon)
A web-based hub for model sharing, VDC knowledge, scripts, and community — think GitHub + StackOverflow for construction modeling.

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Why Not Just Use Revit?

• Revit loads entire models into memory — crashes on large projects
• Trade coordination requires exporting to Navisworks manually
• Civil/site coordination with DWG is painful
• Workflows designed for architects, not contractors

We're building for the people doing VDC coordination every day.

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Current Status

Active development — geometry pipeline working end-to-end on real IFC files.

Working:

• Construction object data model (trade, LOD, CSI code, phase, status)
• Object relationships (dependencies, sequencing, hosting, assemblies)
• Project save/load to .ocm format
• Round-trip JSON serialization
• IFC 4.x and 2x3 parser with entity indexing
• Full geometry extraction pipeline:
  • IFCPRODUCTDEFINITIONSHAPE → IFCSHAPEREPRESENTATION → geometry traversal
  • IFCEXTRUDEDAREASOLID depth extraction
  • IFCTRIANGULATEDFACESET bounding box extraction
  • Unit scale detection (mm, cm, m, ft, in)
  • World matrix computation via IFCLOCALPLACEMENT parent chain
• Tauri 2.0 desktop app with Three.js WebGL viewport
• Trade-color-coded 3D rendering with real IFC dimensions
• Raycasting object selection (click in viewport → highlights in sidebar)
• Bidirectional selection (sidebar ↔ viewport)
• Native file open dialog (.ifc and .ocm)
• Trade filter toggles
• 15 passing unit tests

In Progress:

• Y-axis world position (centroid extraction from faceset geometry)
• Extrusion profile dimension extraction (width/depth from IFCARBITRARYCLOSEDPROFILEDEF)
• Clash detection engine

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Architecture

open-construction-modeler/
├── crates/
│   ├── engine/     — Core data model, relationships, project persistence
│   ├── ifc/        — IFC parser, geometry extraction, world matrix
│   └── app/        — CLI application binary
├── frontend/       — React + TypeScript + Three.js viewport
└── src-tauri/      — Tauri 2.0 desktop shell + Rust command bridge

Language: Rust + TypeScript
Desktop Shell: Tauri 2.0
Rendering: Three.js (WebGL)
Scripting: Python via PyO3 (planned)

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Building

# Install Rust
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

# Install Node.js (v18+) and Tauri CLI
npm install -g @tauri-apps/cli

# Clone and build
git clone https://github.com/coramb2/open-construction-modeler.git
cd open-construction-modeler

# Run tests
cargo test

# Run desktop app (dev mode)
cargo tauri dev

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Roadmap

• Core data model and project persistence
• IFC 4.x/2x3 import
• Tauri desktop app with Three.js viewport
• IFC geometry extraction pipeline
• Y-axis world position from faceset centroids
• Extrusion profile dimension extraction
• Clash detection engine
• BCF 2.1 issue export
• Procore integration
• DWG/DXF civil import
• 4D schedule integration
• Python scripting layer
• Web collaboration platform

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Contributing

This project is in active development. If you work in VDC, construction technology, or Rust systems programming — contributions and feedback are welcome.

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License

Apache-2.0 — see LICENSE