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Urban Terror jump mode

What it is: Urban Terror is a free realistic shooter on the Quake 3 engine (ioquake3). Its jump mode (gametype 9, g_gametype 9) turns off combat and adds timers, routes and save / load positions. A community of mappers and servers (urtjumpmaps / UJM) has built hundreds of jump maps for it. Airtime started here: ut43_icyjumps5d by Rambetter.

Movement#

Quake 3 air control plus UrT's additions (details: mechanics):

  • Run 220 ups, sprint 340, jump velocity 270, friction 4, ground acceleration 5, air acceleration 1.
  • Velocity is snapped to whole numbers every frame, which is why the jump apex is 72.65 units.
  • Stamina: sprinting and jumping cost stamina. g_stamina sets the rules (2 = always full). Tired jumps are 202.5 ups.
  • Walljumps: +200 ups off near-vertical, non-slick walls while −450 < vz < 0, up to 3 per jump by default.
  • Ledge grab, ladders, power slide (landing crouched above 300 ups).
  • Slick / icy surfaces: no friction and no walljumps. Icy maps are built around them: drop-ins, bowls, pipes, slides.

Timing#

  • Entities ut_jumpstart, ut_jumpstop and ut_jumpcancel, touched through trigger_multiple.
  • "type" = the route number (UrT players call routes "ways"). One map can have several routes, each with its own best time.
  • You have to be /ready for the timer to run. Save / load only work when not ready, so practice and timed runs are separate.
  • Times use the server's level time, so run times are multiples of 50 ms at the default sv_fps 20.
  • The UJM servers run Fliserv (custom server) with extra entities: run, speed and stamina filters, ut_jumpcheckpoint and others.

Replays#

UrT demos record server snapshots (positions about every 50 ms), not inputs. They can be watched, but not re-simulated exactly. UJM collects them per map, named by route ("Way: …"). Airtime plays them as ghosts.

What we take#

  • The physics, exactly, and the routes / ready / save rules as the default.
  • The community's maps, demos and knowledge.
  • Leets: one shared jump with exits for different speeds.

What we change#

  • 50 ms timer steps become exact times from our own replays (tech/timing/clock.md).
  • Checkpoints and splits as real features, not server extras.
  • Our own replays: inputs instead of snapshots, so every time can be checked.