This one was done just before I left my room in Gothenburg to go home over Christmas. It was a bit stressful as I wasn’t bringing any machine with the right software to continue working on it with me, but luckily I managed to figure out how to make it work and got it finished the night before leaving :) Interestingly, I believe the red part of this illusion is actually possible, the first design didn’t have the different lanes but was a single solid object as the line version will show.
Trees
2012-12-21
Linework | Fillwork
This construction consists of multiple vertical connections between bars that are perpendicular to each other.
Kyuubimode7 on 
Lee R Vander Baan on 
This one is very cool!
Yeah.
Somehow, the fillwork works better than the linework.
Maybe the inner/outer conflict of perspectives is more exciting than a self-referential conflict.
Very interesting and very cool.