Putting a material onto a Nav Mesh bounds

So, the green area when you press P to see the navigable area in ue4, Is there a way I can parse that data and make a mesh/material from it so I can put it on the ground in game as visual feedback of where its possible to navigate to?

Essentially I want the usability from Steam Vr home or in this video [Mitch's VR Lab Ep08 - UE4 - VR Content Examples - YouTube] (8:13) where it shows you where you can teleport. However I don’t want to have to deal with the spline stuff Mitch does, I’d rather it just have it automatically figure out the area from my currently implemented av Mesh. Plus I don’t see how the way he’s done it would allow for say - a column in the middle of the floor? You wouldn’t be able to wrap the spline around the column unless you could have sub splines inside which you can place. Even so, that’s alot of effort, I’d rather just be able to show/hide a material on my nav mesh…

Or can anyone think of an easier way to do this than what Mitch has done?

Please help!

Cheers.