SolidAI — Autonomous Parametric CAD Agent for SOLIDWORKS

SolidAI is an autonomous, state-aware parametric CAD engineering agent that transforms natural language engineering prompts and 2D blueprints into native, parametric SOLIDWORKS 3D CAD models via the Windows COM API.

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🌟 Key Capabilities

• 💬 Natural Language to 3D CAD: Convert mechanical design prompts ("Design a lightweight robot arm articulation link with weight-reduction pockets, mounting holes, and chamfers") into fully featured SOLIDWORKS models.
• 📐 2D Blueprint Vision to 3D CAD: Extract dimensions, datum faces, multi-view projections (Front, Top, Section), and tolerances from raster technical drawings (.png, .jpg, .bmp) to reconstruct 3D geometry.
• 🌐 Hybrid AI Architecture: Seamlessly switch between Google Gemini (Gemini 2.5 Flash / Pro) for advanced multi-view blueprint reasoning and Ollama / Qwen2.5-Coder for 100% offline local privacy.
• 🛡️ 3-Stage Closed-Loop Self-Healing:
  1. Strict Pydantic Schema Validation: Structural syntax enforcement before execution.
  2. Headless Python CAD Simulator: Static collision, contour overlap, and centerline verification.
  3. Live State-Aware Error Recovery: If SOLIDWORKS returns a COM error or geometric anomaly, SolidAI intercepts the error code, reports feature state back to the LLM, and repairs the plan on a clean document.
• 🧪 Headless CI/CD Testing Suite: Complete in-memory MockCADEngine allowing full benchmark evaluation without requiring a SOLIDWORKS license or Windows COM runtime.

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🏗️ System Architecture

flowchart TD
    User["User Prompt / 2D Blueprint"] --> GUI["Desktop UI (SolidAI_GUI.py)"]
    GUI --> Coordinator["Agent Coordinator (cad_executor.py / vision_analyzer.py)"]
    
    subgraph SG1 ["AI Engine Layer"]
        Coordinator -->|Cloud Multi-View Reasoning| Gemini["Google Gemini (2.5 Flash / Pro)"]
        Coordinator -->|Local Offline Mode| Ollama["Ollama (Qwen2.5-Coder)"]
    end
    
    subgraph SG2 ["Verification and Guardrails"]
        Gemini --> Schema["1. Pydantic Schema Validation (cad_schema.py)"]
        Ollama --> Schema
        Schema --> Sim["2. Headless CAD Dry-Run Simulator (cad_simulator.py)"]
    end
    
    subgraph SG3 ["Execution and Live CAD Layer"]
        Sim --> LiveEngine["3. SolidWorksCADEngine (cad_engine.py)"]
        Sim -.->|Headless CI / Testing| MockEngine["MockCADEngine (mock_engine.py)"]
        LiveEngine --> SW["SOLIDWORKS (Native Parametric 3D Model)"]
        LiveEngine -.->|COM Error / Geometry Anomaly| Coordinator
    end

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🚀 Quick Start

1. Prerequisites

• Operating System: Windows 10 / 11 (64-bit)
• CAD Environment: SOLIDWORKS 2024, 2025, or 2026 installed and activated
• Python: Python 3.10 or higher
• (Optional) Ollama: For 100% offline local model inference (ollama.com)

2. Installation

Clone the repository and install dependencies:

git clone https://github.com/YourUsername/SolidAI.git
cd SolidAI
pip install -r requirements.txt

3. Configuration

Copy the example configuration file:

cp config.example.json config.json

Edit config.json (or enter your key directly inside the GUI):

{
  "GEMINI_API_KEY": "YOUR_GEMINI_API_KEY_HERE"
}

Security Note: config.json is protected by .gitignore and will never be committed to Git.

4. Launching SolidAI

Ensure SOLIDWORKS is open, then launch the agent:

# Using the portable batch launcher
start_solidai.bat

# Or run directly with Python
python SolidAI_GUI.py

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📖 How to Use Manual (User Guide)

SolidAI is designed with an intuitive dual-mode workflow that allows mechanical engineers and designers to move from concept to CAD in seconds.

Mode 1: Natural Language CAD (Text to 3D Model)

1. Launch the Application: Run start_solidai.bat or python SolidAI_GUI.py.
2. Select AI Engine:
   • 🌐 Hybrid (Google Gemini): Cloud-connected reasoning with high dimensional precision and creative geometry optimization.
   • 💻 Local (Ollama / Qwen2.5-Coder): Runs 100% locally on your machine with zero API cost and full data privacy.
3. Select Design Style & Creativity:
   • 🏎️ Aerospace & Racing: Automatically directs the AI to design lightweight parts featuring pocketing, weight-reduction cavities (draw_lightening_pocket), stiffening ribs (draw_stiffening_rib), and edge chamfers.
   • 🏭 Industrial & Heavy-Duty: Generates rigid, thick-walled parts optimized for heavy machining, welding, or casting.
   • 📐 Minimalist & Standard: Constructs exact, direct geometric shapes matching standard geometric dimensions without decorative features.
4. Enter Your Design Requirements:
   • Type your mechanical requirements into the prompt box (e.g., "Design an L-bracket for a NEMA 17 motor with 31 mm mounting pattern, 22 mm center bore, and 4 mm wall thickness").
   • Or click any of the Quick Engineering Templates at the bottom to pre-fill verified mechanical parts (flanges, shafts, brackets, drone frames, pillow blocks).
5. Generate:
   • Click 🚀 Generate Parametric CAD in SOLIDWORKS.
   • SolidAI will synthesize the multi-step parametric action plan, execute a dry-run simulation, and stream the commands into SOLIDWORKS.
   • Within seconds, your 3D model will appear centered and zoomed-to-fit on the SOLIDWORKS viewport!

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Mode 2: Blueprint to 3D CAD (Technical Drawing Vision)

1. Switch to Tab 2: Click on the 📐 Blueprint to 3D CAD tab at the top of the window.
2. Select Technical Drawing Image:
   • Click 📁 Select Blueprint / Drawing (.png, .jpg, .bmp).
   • Choose a photo, scan, or raster image of an engineering drawing or blueprint.
   • A thumbnail preview with dimensions and file size will appear on screen.
3. Add Engineering Directives (Optional):
   • In the notes text box, enter any specific instructions (e.g., "Ensure center bore has H7 tolerance, cut M10 tapped holes at corners").
4. Enter Gemini API Key:
   • Provide your Google Gemini API key in the password field (saved securely in your local session).
5. Generate from Blueprint:
   • Click 🚀 Generate 3D CAD from Blueprint.
   • The Vision Specialist decomposes the drawing into Front, Top, and Section views, resolves dimensions, builds the parametric feature tree, and models the part in SOLIDWORKS.

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💻 Local Offline Setup (Ollama)

If you prefer to run SolidAI without an internet connection or external API keys:

1. Download and install Ollama from ollama.com.
2. Pull the optimized coder model:

   ollama pull qwen2.5-coder:7b

3. SolidAI's start_solidai.bat will automatically start the background Ollama service if it is not already running.
4. In the GUI, select 💻 Local (Ollama / Qwen2.5-Coder) as the AI Engine.

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❓ Troubleshooting & FAQs

• SOLIDWORKS Connection Issues:
  • Ensure SOLIDWORKS is running before clicking Generate. SolidAI connects via Windows COM (win32com.client.Dispatch("SldWorks.Application")).
  • If you see a COM error, restart SOLIDWORKS and run start_solidai.bat.
• What happens if a feature fails?:
  • SolidAI features an automated Self-Healing Loop. If an extrusion or cut encounters a geometric collision or fails in SOLIDWORKS, SolidAI intercepts the exact COM error code and model state, feeds it back to the AI planner, and regenerates a repaired plan on a fresh part document.
• Quota Limits on Free Gemini API:
  • If a model reaches the free-tier rate limit (HTTP 429), SolidAI automatically falls back through its frontier candidate pool (gemini-3-flash-preview $\rightarrow$ gemini-3.8-flash $\rightarrow$ gemini-3.7-flash $\rightarrow$ local Ollama) without crashing.

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📁 Repository Structure

SolidAI/
├── SolidAI_GUI.py            # Modern dark-themed Tkinter GUI (Dual Tab: Prompt & Blueprint)
├── cad_engine.py             # SolidWorksCADEngine: COM API wrapper, unit conversion, 2D/3D operations
├── mock_engine.py            # MockCADEngine: Pure-Python headless in-memory CAD engine for CI/testing
├── cad_executor.py           # Execution engine, streaming, closed-loop self-healing loop
├── cad_schema.py             # Pydantic schema validation & bilingual action mapping
├── cad_simulator.py          # Static dry-run simulator & contour overlap detector
├── agent_prompt.py           # Senior Mechanical Engineer system prompts & few-shot library
├── vision_analyzer.py        # Technical drawing blueprint vision analyzer & prompt compiler
├── parametric_templates.py   # Verified mathematical templates (flanges, shafts, brackets, frames)
├── settings.py               # Safe configuration manager for API keys & model endpoints
├── start_solidai.bat         # Portable launcher script (%~dp0)
├── config.example.json       # Sanitized configuration template
├── requirements.txt          # Python runtime dependencies
├── LICENSE                   # MIT License
├── ARCHITECTURE.md           # In-depth architectural specification and API reference
├── eval/                     # Benchmark suite and automated evaluation tools
│   ├── run_benchmark.py      # Automated 9-case benchmark with fault injection tests
│   └── test_cases.json       # Benchmark geometric specifications
└── tools/                    # Diagnostic and audit utilities
    ├── audit_codebase.py     # Signature verification and API consistency checker
    └── api_probe.py          # Live Gemini and Ollama model endpoint tester

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📊 Verification & Benchmark Suite

SolidAI features a built-in automated test suite measuring volumetric accuracy, body integrity, and fault injection defenses:

python eval/run_benchmark.py

Benchmark Results (100% Pass Rate)

Test Case	Description	Geometric Target	Status
CASE_1	6-Hole Standard Pipe Flange	Single solid body, 6x PCD holes	✅ PASS
CASE_2	NEMA 17 Stepper Motor L-Bracket	Slotted base, 31 mm motor pattern	✅ PASS
CASE_3	3-Step Rotational Transmission Shaft	Multi-step concentric body, chamfers	✅ PASS
CASE_4	Pillow Block Bearing Housing	Bottom slot, central bearing bore, rib	✅ PASS
CASE_5	Stepped Bearing Block (M10 Threaded)	Tapped corner holes, cylindrical hub	✅ PASS
CASE_6	Shift Fork & Clevis Linkage (Drawing 36)	Crescent fork body, pin hole, slot	✅ PASS
CASE_7	Quadcopter 240 mm X-Frame Chassis	Diagonal arms, motor beds, slots	✅ PASS
FAULT_1	Unknown Operation Injection	Caught by Pydantic schema	✅ PROTECTED
FAULT_2	Empty Sketch Extrusion Injection	Caught by static CAD simulator	✅ PROTECTED
FAULT_3	Revolve Without Centerline Injection	Caught by static CAD simulator	✅ PROTECTED

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🛠️ API & Operational Support

SolidAI supports 36+ verified parametric operations including:

• Planes & Faces: select_plane, select_face, select_top_face, select_face_by_ray, create_ref_plane, select_ref_plane
• 2D Sketching: draw_circle, draw_center_rectangle, draw_corner_rectangle, draw_rotated_rectangle, draw_polygon, draw_slot, draw_line_chain, draw_centerline, draw_circular_hole_pattern, draw_rectangular_hole_pattern
• 3D Features: extrude_boss, extrude_cut, revolve_boss, revolve_cut, apply_chamfer, apply_fillet, create_hole_wizard, circular_pattern_last_feature, shell_body

Full API documentation and coordinate transform details can be found in ARCHITECTURE.md.

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🤝 Contributing

Contributions are welcome! Please review CONTRIBUTING.md for pull request guidelines, coding standards, and testing procedures.

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📄 License

This project is licensed under the MIT License - see the LICENSE file for details.