Isogrid and Rutan designs?

[aerogant]

While at Oshkosh this year, I happened to look in the windows of the Scaled planes on display. I noticed a strange dividing of the structure interior. The image below is that of the V-Jet.
Is this an example of isogrid? If so, any thoughts on the benefits / drawbacks in using it?
Any ideas on what the stiffeners would be made of, or how they would be applied?

Thanks in advance.

 

[autoreply]

 

[psween]

 

[karoliina.t.salminen]

 

[psween]

 

[Aircar]