CadQuery Intersection Tool

Overview

This project is a Python-based tool for working with 3D geometry in STEP files using CadQuery. It allows users to define a plane in point-normal form, check for intersections with geometries in a STEP file, and export intersection points to a new STEP file.

Features

• Read and process STEP files
• Define planes using point-normal form
• Check for intersections between the plane and geometries in the STEP file
• Export intersections to a new STEP file if found

---

Installation Instructions (for macOS)

Prerequisites

Ensure Homebrew is installed.

1. Install Python, and OpenCascade:

   brew install python
   brew install opencascade

2. Install uv package manager:

   curl -LsSf https://astral.sh/uv/install.sh | sh

3. Create a virtual environment and install dependencies:

   uv venv
   uv sync

---

Usage

1. Run the Program

   uv run main.py --in-step <STEP_FILE_PATH> --in-plane x y z nx ny nz

   • Replace <STEP_FILE_PATH> with the path to your STEP file.
   • Replace x, y, z, nx, ny, and nz with the point and normal vector of the plane, space-separated e.g.:

     python main.py --in-step random-shape.stp --in-plane 0 0 100 0.2 0.1 1.0

2. Outputs

   • If intersections are found, they are written to intersection.stp in the project directory.
   • If no intersections are found, no new STEP file is created, and a message informs you accordingly.

---

Project Structure

stp_cli/
├── README.md               # Documentation
├── requirements.txt        # Project dependencies
├── main.py                 # Main entry point
├── src/                    # Source code
│   ├── __init__.py         
│   ├── exceptions.py       # custom exceptions
│   ├── domain/             # data structures
│   │   ├── __init__.py
│   │   └── model.py
│   ├── fileio/             # io functions
│   │   ├── __init__.py
│   │   ├── reader.py
│   │   └── writer.py
│   └── geometry/           # 3D processing
│       ├── __init__.py
│       └── engine.py
│
└── tests/                  # Tests
    ├── __init__.py
    ├── conftest.py         # Fixtures
    ├── unit/               # Unit tests
    │   ├── __init__.py
    │   ├── test_fileio.py
    │   ├── test_model.py
    │   └── test_plane.py
    └── integration/        # Integration tests
        ├── __init__.py
        └── test_workflow.py

---

Testing

Run the test suite using pytest:

uv run pytest

Sample Tests

• File Reading Tests:
  • Check if the STEP file is correctly read
  • Validate error handling for non-existent or invalid files
• Intersection Tests:
  • Verify that intersections are detected and written to the output STEP file
  • Ensure no output file is created when no intersections are found

---

Dependencies

• CadQuery
• Python 3.11+
• uv package manager

---

Known Issues and Limitations

1. The tool assumes valid STEP files as input; invalid or malformed files may cause unexpected errors.
2. Intersection detection depends on the geometric complexity of the input model.

---