[32bitkid]

I'm glad to see other people working on this kind of stuff. The old Descent games had a related—although more primitive—rendering engine that could be (ab)used to similar effect that was a lot of fun back in the mid-90's. Some of the home-brew levels back in the day exploited this for some pretty mind-bending overlapping non-euclidian level design.

As for myself, I've been working on a 2d-space combat game set on the surface of a Poincaré Disk as a hobby over the past few years, not sure i'll ever do anything with it for real, but it's fun.

[lsh]

Duke Nukem 3D/Shadow Warrior and the Build engine also achieved a number of their effects and mechanisms similar to the video. In fact, the very first level in the first episode of Duke Nukem 3D where you're on a rooftop, pick up the pistol, shoot the fan and drop down the shaft is a perfect example - that rooftop and the street level you drop into are connected seamlessly by a short tunnel that transports you. Water surfaces were also used in this effect and the 'underwater' parts were often entirely other parts of the map.

I always thought of them of as pre 'true' 3D engine hacks, but it was so cool to see them again in that video. Cooler still that it's essentially the same trick being used in Portal and I never tweaked to it

[the8472]

Yeah, that was amazing. It couldn't do scale-variations but nested volumes and one-sided portals could make the 6DoF navigation even more complicated and it was also possible to build interesting ambushes with that.