Recast & Detour

Recast

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

Recast is...

• 🤖 Automatic - throw any level geometry at it and you will get a robust navmesh out
• 🏎️ Fast - swift turnaround times for level designers
• 🧘 Flexible - easily customize the navmesh generation and runtime navigation systems to suit your specific game's needs.

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 stiching together the generated 2d plygonal regions.

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.

RecastDemo

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

Building RecastDemo

RecastDemo uses premake5 to build platform specific projects. Download it and make sure it's available on your path, or specify the path to it.

Linux

• Install SDL2 and its dependencies according to your distro's guidelines.
• Navigate to the RecastDemo folder and run premake5 gmake2
• Navigate to RecastDemo/Build/gmake2 and run make
• Navigate to RecastDemo/Bin and run ./RecastDemo

macOS

• Grab the latest SDL2 development library dmg from here and place SDL2.framework in RecastDemo/Bin
• Navigate to the RecastDemo folder and run premake5 xcode4
• Open Build/xcode4/recastnavigation.xcworkspace
• Set the RecastDemo project as the target and build.

Windows

• Grab the latest SDL2 development library release from here and unzip it RecastDemo\Contrib. Rename the SDL folder such that the path RecastDemo\Contrib\SDL\lib\x86 is valid.
• Navigate to the RecastDemo folder and run premake5 vs2022
• Open Build/vs2022/recastnavigation.sln.
• Set RecastDemo as the startup project, build, and run.

Running Unit tests

• Follow the instructions to build RecastDemo above. Premake should generate another build target called "Tests".
• Build the "Tests" project. This will generate an executable named "Tests" in RecastDemo/Bin/
• Run the "Tests" executable. It will execute all the unit tests, indicate those that failed, and display a count of those that succeeded.

Integrating with your game or engine

It is recommended to add the source directories DebugUtils, Detour, DetourCrowd, DetourTileCache, and Recast into your own project depending on which parts of the project you need. For example your level building tool could include DebugUtils, Recast, and Detour, and your game runtime could just include Detour.

Install through vcpkg

If you are using the vcpkg dependency manager you can download and install Recast with:

vcpkg install recast

Contribute

Check out the Project Roadmap to see what features and functionality you might be able to help with, and the Contributing doc for guidance on making contributions.

Discuss

• Discuss Recast & Detour: http://groups.google.com/group/recastnavigation
• Development blog: http://digestingduck.blogspot.com/

License

Recast & Detour is licensed under ZLib license, see License.txt for more information.