I'm trying to render some IBody2 objects using opengl in the BufferSwap callback. I do this by iterating the faces and calling

   face.GetTessTriStrips

For some of my bodies this works and I can render the triangle strips successfully with opengl using OpenTK. With other bodies the call just returns System.DBNull. It's like the tessellation of the face has not been performed. I would then expect to find an API call to force tessellation but I can't find it.  Is there an API to force tessellation on a face when in the context of the BufferSwap callback.

Maybe the bufferswap callback is the wrong place to get the tessellation data.

My scene is pretty simple. I have a concurrent dictionary to store my bodies to render

        public static ConcurrentDictionary> BodiesToRender = new ConcurrentDictionary>();

and a static method to display them. This returns a disposable that when disposed removes the body from the scene.

        public static IDisposable DisplayUndoable(IBody2 body, Color? color)

        {

            BodiesToRender[body]=Tuple.Create(body,(color ?? Color.Yellow));

            return Disposable.Create(() =>

            {

                Tuple dummy;

                BodiesToRender.TryRemove(body, out dummy);

            });

        }

and in BufferSwap I have

        private int OnBufferSwapNotify()

        {

            foreach (var o in BodiesToRender.Values)

            {

                var b = o.Item1;

                MeshRender.Render(b.GetFaces().CastArray(), _ISwApp, o.Item2, 2.0f);

            }

      }

The MeshRender.Render method is the one that calls GetTessTriStrips.