Recast Version 1.0

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

    * It is automatic, which means that you can throw any level geometry
      at it and you will get robust mesh out
    * It is fast which means swift turnaround times for level designers
    * It is open source so it comes with full source and you can
      customize it to your hearts content. 

The Recast process starts with constructing a voxel mold from a level geometry 
and then casting a navigation mesh over it. The process consists of three steps, 
building the voxel mold, partitioning the mold into simple regions, peeling off 
the regions as simple polygons.

   1. The voxel mold is build from the input triangle mesh by rasterizing 
      the triangles into a multi-layer heightfield. Some simple filters are 
      then applied to the mold to prune out locations where the character 
      would not be able to move.
   2. The walkable areas described by the mold are divided into simple 
      overlayed 2D regions. The resulting regions have only one non-overlapping 
      contour, which simplifies the final step of the process tremendously.
   3. The navigation polygons are peeled off from the regions by first tracing 
      the boundaries and then simplifying them. The resulting polygons are 
      finally converted to convex polygons which makes them perfect for 
      pathfinding and spatial reasoning about the level. 

The toolset code is located in the Recast folder and demo application using the Recast
toolset is located in the RecastDemo folder.

The project files with this distribution can be compiled with Microsoft Visual C++ 2008
(you can download it for free) and XCode 3.1.

--

Release Notes

----------------
* Recast 1.0
  Released March 29th, 2009

This is the first release of Recast.

The process is not always as robust as I would wish. The watershed phase sometimes swallows tiny islands
which are close to edges. These droppings are handled in rcBuildContours, but the code is not
particularly robust either.

Another non-robust case is when portal contours (contours shared between two regions) are always
assumed to be straight. That can lead to overlapping contours specially when the level has
large open areas.



Mikko Mononen
memon@inside.org