: : How are things like this defined in marathon maps? I mean, if true bridges
: are impossible, how is room over room like this possible?
: Marathon's engine is portal-based. Each line of a polygon is either solid, or
: a portal connection to another polygon. The renderer chokes if it tries to
: draw more than one open space along a vertical line, such as the area
: above and below a bridge, but that's more a rendering limitation rather
: than a map-format limitation. As long as you can't see vertically
: overlapping spaces simultaneously, you can actually have them exist.
: A fully specified Marathon coordinate is not (x,y) or even (x,y,z), but
: (x,y,z,polygon). As the player (or monster or projectile) moves across
: portal boundaries, it updates the polygon coordinate. Within the maps,
: polygons can overlap not just on top of each other, but fully in (x,y,z)
: space, which leads to "5-D Space" as seen in the eponymous map,
: or places like the southeast hall in Couch Fishing. There, you see either
: the hall or the sunken room, but not both within the same vertical space
: so it's OK.
Thanks so much for this. Seriously, this is literally what I was trying to remember about the A1 engine when I started this thread.