MESGRO Scripts

Utility scripts for the MESGRO (Mechanical, Electrical, Software Gallery for Robots) project.

📂 Where to Put Your Files

All converted models should go in the assets/ folder:

assets/
├── images/projects/your-project/    # Project images
│   ├── featured.jpg                 # Main image
│   └── gallery/                     # Additional photos
├── models/your-project/             # 🤖 3D Models (GLTF/GLB)
│   ├── base.gltf                    # Converted from STL/STEP
│   └── assembly.gltf
└── schematics/your-project/         # ⚡ Circuit diagrams
    └── main-board.svg

CAD-to-GLTF Converter

Converts CAD files (STL, STEP) to optimized GLTF format for web-based 3D viewing on GitHub Pages.

Supported Formats

Format	Extension	Status	Notes
STL	`.stl`	✅ Fully Supported	Universal mesh format
STEP	`.step`, `.stp`	✅ Fully Supported	CAD exchange format
SolidWorks	`.sldprt`, `.sldasm`	❌ Not Supported	Export to STL/STEP first
Autodesk	`.f3d`, `.iam`, `.ipt`	❌ Not Supported	Export to STL/STEP first

Why are SolidWorks and Autodesk formats not supported?

These are proprietary, closed-source formats. No open-source Python libraries exist to read them because:

File format specifications are not publicly documented

Reading them would require reverse-engineering or licensing agreements

They contain parametric/feature data, not just geometry

Solution: Export your models to STL or STEP from your CAD software:

SolidWorks: File → Save As → STL or STEP

Fusion 360: File → Export → STL or STEP

Inventor: File → Export → CAD Format → STL or STEP

Installation

Option 1: Using Conda (Recommended)

# Create conda environment
conda create -n mesgro python=3.11 -y

# Activate environment
conda activate mesgro

# Install dependencies
pip install -r scripts/requirements.txt

Option 2: Using pip directly

pip install trimesh numpy cadquery-ocp

Usage

Basic Conversion

# Activate conda environment first
conda activate mesgro

# Convert STL to GLTF
python scripts/cad_to_gltf.py -i model.stl -o output.gltf

# Convert STEP to GLTF
python scripts/cad_to_gltf.py -i assembly.step -o output.gltf

Check STEP Support

python scripts/cad_to_gltf.py --check-step

Command Line Options

Option	Description
`-i`, `--input_file`	Input CAD file (.stl, .step, .stp)
`-o`, `--output_file`	Output GLTF file
`--check-step`	Check if STEP support is installed
`-h`, `--help`	Show help message

Examples

# Convert a robot arm STL
python scripts/cad_to_gltf.py -i assets/models/robotic-arm/base.stl -o assets/models/robotic-arm/base.gltf

# Convert a STEP assembly
python scripts/cad_to_gltf.py -i designs/sensor-housing.step -o assets/models/iot-monitor/housing.gltf

# Batch convert multiple files (PowerShell)
Get-ChildItem -Filter "*.stl" | ForEach-Object {
    $output = $_.BaseName + ".gltf"
    python scripts/cad_to_gltf.py -i $_.FullName -o $output
}

Output Format

The converter outputs GLTF files with:

Embedded binary data - No external .bin files needed
Optimized mesh - Merged vertices, removed degenerate faces
Web-ready - Compatible with Google Model Viewer and three.js

Troubleshooting

“STEP support not installed”

Install the OpenCASCADE bindings:

pip install cadquery-ocp

“Module not found: trimesh”

Install core dependencies:

pip install trimesh numpy

Large output file size

For very large models, consider:

Simplifying the mesh in your CAD software before export
Using mesh decimation tools
Exporting at lower resolution from CAD software

SPICE-to-SVG Schematic Generator

Converts SPICE netlists to SVG schematics. See spice_to_svg.py for usage.

Dependencies

All dependencies are listed in requirements.txt:

trimesh>=4.0.0      # Mesh loading and GLTF export
numpy>=1.24.0       # Numerical operations
cadquery-ocp>=7.8.0 # STEP file support (OpenCASCADE)