GmshSharp

A comprehensive C# wrapper for the Gmsh mesh generation library, providing high-level APIs for creating finite element meshes programmatically.

Overview

GmshSharp is a .NET binding for Gmsh, a three-dimensional finite element mesh generator with a built-in CAD engine and post-processor. This library provides a native C# interface to Gmsh's powerful mesh generation capabilities, making it easy to create complex geometries and meshes directly from your .NET applications.

Features

• Complete Gmsh API Coverage: Full access to Gmsh's geometry, meshing, and post-processing capabilities
• Multi-Target Support: Compatible with .NET 8.0 and .NET Framework 4.8
• Type Safety: Strongly-typed C# API with nullable reference types support (.NET 8.0)
• Memory Safe: Proper resource management and memory handling
• Cross-Platform: Works on Windows, macOS, and Linux
• Tutorial Examples: Complete C# ports of Gmsh's official Python tutorials (T1-T5)

Project Structure

GmshSharp/
├── GmshSharp.Native/     # Low-level P/Invoke bindings to native Gmsh library
├── GmshSharp.Core/       # High-level C# API and abstractions
└── GmshSharp.Tutorials/  # Example applications and tutorials

Quick Start

Prerequisites

• .NET 8.0 SDK or .NET Framework 4.8
• Native Gmsh libraries (included in native-libs/ directory)

Important:

This project targets Gmsh version 4.14. You must place the appropriate native library files for Gmsh 4.14 (.dll for Windows, .dylib for macOS, .so for Linux) into the native-libs/gmsh_lib/ directory. Only the required library for your platform is necessary. The repository does not include these files by default; please obtain them from the official Gmsh 4.14 releases or your system package manager. These files are included in the Gmsh SDK distribution for each platform.

The native-libs/gmsh_lib/ directory is git-ignored except for a .gitkeep file, so you need to add the native library manually after cloning the repository.

Basic Usage

using GmshSharp.Tutorials;

// Initialize Gmsh
Gmsh.Initialize();

// Create a new model
Gmsh.Model.Add("example");

// Define mesh size
double lc = 1e-2;

// Create geometry
var p1 = Gmsh.Model.Geo.AddPoint(0, 0, 0, lc);
var p2 = Gmsh.Model.Geo.AddPoint(1, 0, 0, lc);
var p3 = Gmsh.Model.Geo.AddPoint(1, 1, 0, lc);
var p4 = Gmsh.Model.Geo.AddPoint(0, 1, 0, lc);

// Create lines
var l1 = Gmsh.Model.Geo.AddLine(p1, p2);
var l2 = Gmsh.Model.Geo.AddLine(p2, p3);
var l3 = Gmsh.Model.Geo.AddLine(p3, p4);
var l4 = Gmsh.Model.Geo.AddLine(p4, p1);

// Create surface
var curveLoop = Gmsh.Model.Geo.AddCurveLoop(new[] { l1, l2, l3, l4 });
var surface = Gmsh.Model.Geo.AddPlaneSurface(new[] { curveLoop });

// Synchronize and generate mesh
Gmsh.Model.Geo.Synchronize();
Gmsh.Model.Mesh.Generate(2);

// Save mesh
Gmsh.Write("output.msh");

// Cleanup
Gmsh.Shutdown();

Running Tutorials

The project includes complete C# implementations of Gmsh's official tutorials:

// Run individual tutorials
T1.Run(); // Basic geometry and meshing
T2.Run(); // Transformations, extrusions, volumes
T3.Run(); // Extruded meshes, ONELAB parameters
T4.Run(); // Built-in CAD kernel features
T5.Run(); // Mesh sizes, fields

Or run all tutorials:

cd GmshSharp/GmshSharp.Tutorials
dotnet run

Building from Source

1. Clone the repository:

   git clone https://github.com/yourusername/GmshSharp.git
   cd GmshSharp

2. Build the solution:

   dotnet build GmshSharp/GmshSharp.sln

3. Run the tutorials:

   dotnet run --project GmshSharp/GmshSharp.Tutorials

API Documentation

Core Classes

• Gmsh: Main entry point for Gmsh operations
• Gmsh.Model: Model management and operations
• Gmsh.Model.Geo: Built-in CAD kernel for geometry creation
• Gmsh.Model.Mesh: Mesh generation and manipulation
• Gmsh.View: Post-processing and visualization

Key Methods

• Gmsh.Initialize(): Initialize the Gmsh library
• Gmsh.Model.Add(name): Create a new model
• Gmsh.Model.Geo.AddPoint(x, y, z, meshSize): Add a point
• Gmsh.Model.Geo.AddLine(startPoint, endPoint): Add a line
• Gmsh.Model.Geo.Synchronize(): Synchronize CAD model
• Gmsh.Model.Mesh.Generate(dim): Generate mesh (1D, 2D, or 3D)
• Gmsh.Write(filename): Export mesh to file
• Gmsh.Shutdown(): Clean up resources

Supported Platforms

• Windows: x64, x86
• macOS: x64, ARM64
• Linux: x64, ARM64

Native libraries for all platforms are included in the native-libs/ directory.

Examples and Tutorials

The GmshSharp.Tutorials project contains complete implementations of Gmsh's official tutorials:

• T1: Basic geometry creation, elementary entities, physical groups
• T2: Transformations, extrusions, volumes
• T3: Extruded meshes, ONELAB parameters
• T4: Built-in CAD kernel features, boolean operations
• T5: Mesh sizes, characteristic lengths, background fields

Contributing

Contributions are welcome! Please feel free to submit issues, feature requests, or pull requests.

Acknowledgments

• Gmsh development team for creating the excellent mesh generation library
• Built with inspiration from Gmsh's official Python API