🧊 Online 3D STL Viewer & Geometry Analyzer

English Version | 中文版 (Chinese Version)

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🌟 Overview

Online 3D STL Viewer & Geometry Analyzer is a modern, high-performance, browser-based WebGL application designed for 3D printing enthusiasts, CAD designers, mechanical engineers, and makers.

It allows you to open, view, inspect, and measure Binary and ASCII .stl 3D files instantly with zero software installation and 100% local client-side data privacy.

👉 Live Demo: https://open-stl-file.github.io/
👉 中文版 (Chinese Demo): https://open-stl-file.github.io/zh/

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✨ Key Features

• 🚀 Instant Client-Side Parsing: Parses both Binary and ASCII STL files in milliseconds using pure JavaScript DataView. Zero server uploads required.
• 🎨 CAD Technical Edges Mode: Features a dedicated crisp engineering outline rendering style (THREE.EdgesGeometry) paired with flat shading on pure light background—matching authentic technical drawing aesthetics.
• 📊 3D Geometry Analytics: Automatically computes 3D Bounding Box dimensions ($X \times Y \times Z$ mm), total volume ($cm^3$), surface area ($cm^2$), triangle count, and vertex count.
• ⚖️ 3D Printing Material Weight Estimator: Instant weight calculation ($g$) for PLA, ABS, PETG, Resin, Aluminum, and Stainless Steel filaments.
• ✂️ Dynamic Section Clipping Plane: Axis-aligned ($X/Y/Z$) slicing plane to inspect interior hollow geometry, core structures, and wall thickness.
• 📏 Point-to-Point 3D Measurement: Raycast interactive spatial distance measurement between any two points on the 3D surface.
• 🗿 Pre-Loaded 3D Models:
  1. ♾️ Möbius Strip Sculpture: Iconic single-surface topological geometry sculpture in cyan metallic finish.
  2. 🏛️ Temple of Heaven (Beijing): Architectural masterpiece with 3-tiered marble altar, red columns, and triple-tier royal blue roofs.
  3. ⚙️ Mechanical Spur Gear: Precision 16-tooth transmission gear ideal for CAD outline inspection.
• 🌈 15-Bit RGB Vertex Color Support: Full binary STL 15-bit color attribute parsing and rendering.

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📁 Repository Structure

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├── index.html              # Root English homepage (https://open-stl-file.github.io/)
├── zh/
│   └── index.html          # Chinese homepage (https://open-stl-file.github.io/zh/)
├── style.css               # Glassmorphism UI stylesheet
├── js/
│   ├── stlParser.js        # High-performance Binary & ASCII STL parser
│   ├── samples.js          # Procedural 3D model generator (Möbius, Temple, Gear)
│   └── app.js              # Three.js WebGL controller & analytics engine
├── .github/
│   └── workflows/
│       └── deploy.yml      # Zero-token automated GitHub Pages CI/CD workflow
├── README.md               # English documentation
└── README.zh-CN.md         # Chinese documentation

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🛠️ Technology Stack

• 3D Engine: Three.js (WebGL Renderer, OrbitControls, PCFSoftShadowMap)
• UI Design: Modern Glassmorphism layout with CSS Custom Properties & Google Fonts (Inter & JetBrains Mono)
• Icons: FontAwesome 6
• Deployment: GitHub Actions + GitHub Pages

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🌐 Local Setup

Simply clone the repository and serve static files locally:

git clone https://github.com/open-stl-file/open-stl-file.github.io.git
cd open-stl-file.github.io
# Start a local HTTP server
python -m http.server 8080

Open http://localhost:8080/ in your browser.

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📄 License

This project is licensed under the MIT License.