How do I make a face between the inside of an outer mesh with the outside of an inner mesh? I have a racetrack in the middle of a bounding area.  I would like to join the two meshes and make faces between the square bounding area and the outside of the racetrack.

I have the relevant vertices of the racetrack saved as a vertex group.



Here is my blend file if it is required...

blend file

Or perhaps there is a better approach.  My ultimate goal is to have a plane outside the racetrack that will anchor objects for scenery in a video game.

Thanks for any help.
I was able to do it by selecting the vertex group with the outer 4 vertices of the bounding box and then Mesh -&gt; Faces -&gt; Fill or Alt F to "Fill a selected edge loop with faces".  I'm still open to a solution that is more correct.