A TA map always consists of two components: the TNT (the actual terrain) and the OTA (parameters, start positions, mission settings).
How a map gets into the game
A map ships either as a .ufo archive (drop it into the TA folder) or as loose
.tnt + .ota files, which can simply be copied into the game’s maps folder —
the game loads those at startup. Both distribution forms are equivalent; the
archive form just wraps the same two files. (Engine behaviour confirmed by
Michael, Oct 2026.)
The cell logic
- 1 map “unit” = 512×512 pixels = 16×16 cells of 32×32 pixels.
- An “8x8” map = 128×128 cells = 4096×4096 pixels of terrain.
- Elevation: TNT stores a height per cell; TA interpolates hills and valleys from it.
Tools
- TAE (TA Editor / Mission Editor) — Cavedog’s own editor, buggy in early versions, but the classic.
- Annihilator — community tool for maps and mission design, much more stable than TAE.
- Terragen + converter — render realistic landscapes in Terragen, then convert to TNT.
- YankTherm / TA:HPI tools — to pack TNT/OTA into a UFO/HPI archive.
The workflow (classic)
- Design the terrain base shape (heightmap, waterline).
- Apply textures (ground, cliffs, water, feature placement).
- Fill in the OTA file: start positions, wind (critical for energy balance!), gravity.
- Pack into UFO/HPI, drop into the TA folder, test.
- Balance check: start positions fair? Metal extractors symmetric? Wind decent?
What the pros watch out for
- Start positions: the .schema in the OTA defines 2/3/4-player setups.
- Metal: place metal extractors symmetrically, but keep some variation (map control).
- LOS bug: Cavedog’s original LoS table (v1.1) has a bug — limits sight to 288px. Community patches exist (McnTerra-NS.ufo contains a corrected table).
- Water: “acid” in the OTA makes water toxic; water level shapes entire play styles (hover maps!).
Sources (partly offline, but archived)
- TA Map Design Guide (1999)
- YouTube: How To Make Maps For TA
- File Universe: map-building tools live under “Utilities”.