Update other_libs.md

docs/other_libs.md

@@ -73,9 +73,10 @@ geometry math     |  [Tomas Akenine-Moller snippets](http://tinyurl.com/ht79ndj)
 geometry math     |  [Clipper](http://www.angusj.com/delphi/clipper.php)                  | Boost                | C++ |  2  | line & polygon clipping & offsetting
 geometry math     |  [PolyPartition](https://github.com/ivanfratric/polypartition)        | MIT                  | C++ |  2  | polygon triangulation, partitioning
 geometry math     |  [Voxelizer](https://github.com/karimnaaji/voxelizer)                 | MIT                  |C/C++|**1**| convert triangle mesh to voxel triangle mesh
-geometry math     |  [yocto_bvh.h](https://github.com/xelatihy/yocto-gl)                  | MIT                  |C/C++|**1**| ray-casting of bounding-volume hierarchy
+geometry math     |  [yocto_bvh.h](https://github.com/xelatihy/yocto-gl)                  | MIT                  |C/C++|**1**| ray-casting and closest-element queries of bounding-volume hierarchy
 geometry math     |  [yocto_shape.h](https://github.com/xelatihy/yocto-gl)                | MIT                  |C/C++|**1**| shape generation, tesselation, normals, etc.
-geometry math     |  [yocto_trace.h](https://github.com/xelatihy/yocto-gl)                | MIT                  |C/C++|**1**| physically-based unidirectional path tracer w/ MIS for direct lights
+graphics (3d)     |  [yocto_trace.h](https://github.com/xelatihy/yocto-gl)                | MIT                  |C/C++|**1**| physically-based unidirectional path tracer w/ MIS for direct lights
+graphics (3d)     |  [yocto_symrigid.h](https://github.com/xelatihy/yocto-gl)                | MIT                  |C/C++|**1**| rigid body simulator (sequential impulse/PGS) with support for concave objects
 graphics (2d)     |  [blendish](https://bitbucket.org/duangle/oui-blendish/src)           | MIT                  |C/C++|**1**| blender-style widget rendering
 graphics (2d)     |  [tigr](https://bitbucket.org/rmitton/tigr/src)                       | **public domain**    |C/C++|  2  | quick-n-dirty window text/graphics for Windows and OSX
 graphics (2d)     |  [noc_turtle](https://github.com/guillaumechereau/noc)                | MIT                  |C/C++|  2  | procedural graphics generator