DotRecast : C# Recast & Detour

DotRecast is a port of C++'s recastnavigation and Java's recast4j to the C# language.

📹 Youtube

🚀 Features

• 🤖 Automatic - Recast can generate a navmesh from any level geometry you throw at it
• 🏎️ Fast - swift turnaround times for level designers
• 🧘 Flexible - detailed customization options and modular design let you tailor functionality to your specific needs
• 🚫 Dependency-Free - building Recast & Detour only requires a .NET compiler
• 💪 Industry Standard - Recast powers AI navigation features in Unity, Unreal, Godot, O3DE and countless AAA and indie games and engines

Recast Navigation is divided into multiple modules, each contained in its own folder:

• DotRecast.Recast: Navmesh generation
• DotRecast.Detour: Runtime loading of navmesh data, pathfinding, navmesh queries
• DotRecast.Detour.TileCache: Navmesh streaming. Useful for large levels and open-world games
• DotRecast.Detour.Crowd: Agent movement, collision avoidance, and crowd simulation
• DotRecast.Recast.Dynamic: robust support for dynamic nav meshes combining pre-built voxels with dynamic objects which can be freely added and removed
• DotRecast.Recast.Extras: simple tool to import navmeshes created with A* Pathfinding Project
• DotRecast.Recast.Toolset: sdk
• DotRecast.Recast.Demo: Standalone, comprehensive demo app showcasing all aspects of Recast & Detour's functionality
• test/DotRecast.*.Test: Unit tests

DotRecast.Recast

Recast is state of the art navigation mesh construction toolset for games.

Recast constructs a navmesh through a multi-step rasterization process:

1. First Recast voxelizes the input triangle mesh by rasterizing the triangles into a multi-layer heightfield.
2. Voxels in areas where the character would not be able to move are removed by applying simple voxel data filters.
3. The walkable areas described by the voxel grid are then divided into sets of 2D polygonal regions.
4. The navigation polygons are generated by triangulating and stitching together the generated 2d polygonal regions.

DotRecast.Detour

Recast is accompanied by Detour, a path-finding and spatial reasoning toolkit. You can use any navigation mesh with Detour, but of course the data generated with Recast fits perfectly.

Detour offers a simple static navmesh data representation which is suitable for many simple cases. It also provides a tiled navigation mesh representation, which allows you to stream of navigation data in and out as the player progresses through the world and regenerate sections of the navmesh data as the world changes.

DotRecast.Recast.Demo

You can find a comprehensive demo project in the DotRecast.Recast.Demo folder. It's a kitchen sink demo showcasing all the functionality of the library. If you are new to Recast & Detour, check out SoloNavMeshBuilder.cs to get started with building navmeshes and TestNavmeshTool.cs to see how Detour can be used to find paths.

Building DotRecast.Recast.Demo

1. DotRecast.Recast.Demo uses dotnet 8 to build platform specific projects. Download it and make sure it's available on your path, or specify the path to it.
2. Open a command prompt, point it to a directory and clone DotRecast to it: git clone https://github.com/ikpil/DotRecast.git
3. Open <DotRecastDir>\DotRecast.sln with Visual Studio 2022 and build DotRecast.Recast.Demo
   • Optionally, you can run using the dotnet run command with DotRecast.Recast.Demo.csproj

Windows

• need to install microsoft visual c++ redistributable package

Linux & macOS & Windows

• Navigate to the DotRecast.Recast.Demo folder and run dotnet run

Running Unit tests

With VS2022

• In Visual Studio 2022 go to the test menu and press Run All Tests

With CLI

• in the DotRecast folder open a command prompt and run dotnet test

Integrating with your game or engine

It is recommended to add the source directories DotRecast.Core, DotRecast.Detour.Crowd, DotRecast.Detour.Dynamic, DotRecast.Detour.TitleCache, DotRecast.Detour.Extras and DotRecast.Recast into your own project depending on which parts of the project you need. For example your level building tool could include DotRecast.Core, DotRecast.Recast, and DotRecast.Detour, and your game runtime could just include DotRecast.Detour.

Discuss

• discussions:
  • https://github.com/recastnavigation/recastnavigation/discussions
• issues:
  • https://github.com/ikpil/DotRecast/issues or
  • https://github.com/recastnavigation/recastnavigation/issues

License

DotRecast is licensed under ZLib license, see LICENSE.txt for more information.