OTA

The OTA file is one of the two components of a Total Annihilation map or mission. The second component is the TNT file. The OTA file contains text information that describes properties of a map/mission, such as the planet type, narration, tidal strengths, wind speeds, gravity, and unit starting positions and orders. OTA and TNT files are found side-by-side in the maps subdirectory, and should be given the same filename for consistency.

Within OTA files is the concept of schemas. Each schema is a slight variation on the map and/or mission based on difficulty (easy, medium, or hard) or if it is a multiplayer map. Many variables that are set in a particular OTA file are specific to all schemas (such as the map size, etc.), but they can be altered, added, or removed for different schemas. For example, you could place extra metal deposits, trees, or steam vents on easier schemas, or add additional computer units for harder schemas.

In addition to units and features, OTA files also contain what are simply called "special" objects. The "special" objects are simply the 10 starting positions that are placed in the map's multiplayer schema to determine where everybody starts on the map.

In most cases, your OTA file will be generated for you by map/mission editing tools such as TAE (comes with The Core Contingency) and Kinboat's Annihilator (man, he's a busy guy!). However, it could be helpful to understand the contents of this file in case you want to do any fine-tuning of your own.

A small example from the Core Contingency's Biggie Biggs multiplayer map:

[GlobalHeader]
    {
    missionname=Biggie Biggs;
    missiondescription=36 X 16 Dance from island to island crushing your opponents.;
    planet=Slate;
    missionhint=;
    brief=;
    narration=;
    glamour=;
    lineofsight=1;
    mapping=1;
    tidalstrength=20;
    solarstrength=20;
    lavaworld=1;
    killmul=50;
    timemul=0;
    minwindspeed=3500;
    maxwindspeed=5000;
    nosealeveltrigger=1;
    gravity=112;
    maxunits=200;
    waterdoesdamage=0;
    waterdamage=100;
    numplayers=2, 4, 6, 8, 10;
    size=36 x 16;
    memory=32 mb;
    useonlyunits=biggie biggs.tdf;
    SCHEMACOUNT=1;
    [Schema 0]
        {
        Type=Network 1;
        aiprofile=AirBattle;
        SurfaceMetal=3;
        MohoMetal=40;
        HumanMetal=1000;
        ComputerMetal=1000;
        HumanEnergy=1000;
        ComputerEnergy=1000;
        MeteorWeapon=earthquake;
        MeteorRadius=650;
        MeteorDensity=.4;
        MeteorDuration=4;
        MeteorInterval=700;
        [specials]
            {
            [special0]
                {
                specialwhat=StartPos7;
                XPos=1216;
                ZPos=3840;
                }
            [special1]
                {
                specialwhat=StartPos8;
                XPos=16112;
                ZPos=3312;
                }
            .....
            }
        }
    }

Within the OTA file that describes a mission associated with a map, you will typically have additional schemas defined that will look similar to this piece from the Core Contingency's ARM Mission 1 OTA file:

.....

SCHEMACOUNT=3;
[Schema 0]
    {
    Type=Easy;
    aiprofile=Waterwrld;

    .....

    [units]
        {

        .....

        [unit13]
            {
            Unitname=CORCS;
            Ident=;
            XPos=3216;
            YPos=0;
            ZPos=1184;
            Player=2;
            HealthPercentage=100;
            Angle=0;
            Kills=0;
            InitialMission=w 900,p 1416 852,;
            }

        .....

        [unit18]
            {
            Unitname=CORPLAT;
            Ident=;
            XPos=4192;
            YPos=0;
            ZPos=1040;
            Player=2;
            HealthPercentage=100;
            Angle=180;
            Kills=0;
            InitialMission=w 920,b CORSEAP 1,w 300,b CORSEAP 1, ....;
            }

        .....

        }
    [features]
        {
        [feature0]
            {
            Featurename=WaterAquaOre3;
            XPos=362;
            ZPos=427;
            }
        }
    [specials]
        {
        [special0]
            {
            specialwhat=StartPos1;
            XPos=5696;
            ZPos=6816;
            }
        }
    }
[Schema 1]
    {

    .....

    }

.....

Within the OTA files, the following variables can be set for the particular map, mission, schema, unit, or special object.

Initial Mission Commands

The Initial Mission selection is the true heart of mission creation. Most missions created do not rely on the AI to handle the battle, rather, everything is carefully planned ahead. Having units wait until they are attacked, having groups of units attack at the same time, having them target specific units, even roving patrols, are all commands that are set here. Giving all (or most) of your enemy units a series of commands that interact and mesh to make an appropriate defense (and offense) is what mission creation is all about. If a Unit is given no initial commands, or runs out of commands, the AI will take over, if it is a Computer controlled Unit (anything other than Player 1). If it is a Player controlled Unit and you want the Player to be able to interrupt the initial commands, insert a "s" (to make it selectable) in the initial command list.

What follows is a list of the available commands; use a comma to separate commands. Remember that all unit references should be to the unit’s short name, not the unit’s description (e.g. CORTL not Core Torpedo Launcher).

Short example scenario:

Let’s say for a moment, that you’re in the middle of creating an Arm mission, for which the goal is to get your squad of Zeus into the enemy’s base and take out their fusion plant. While setting up the defenses, you might program a fleet of Rapier gunships to wait until the Arm lightning-chuckers have destroyed a radar tower abandoned in the middle of a valley, move to co-ordinates 513, 700, followed by a run on the Arm Commander, nestled in it’s camp. To spring your little trap, you would need to do the following setup.

1. Place a radar tower with unique name (e.g. "TRAP")
2. Place some Rapier units, each with the following initial command string:
   

   wa TRAP, a ARMZEUS, m 513 700, a ARMCOM

It’s important to make sure that you’ve provided the player with at least one Zeus unit to start with. If there is no Zeus units on the map, the Rapiers will simply skip the command "a ARMZEUS" and go straight after the Commander. The radar tower does not need to be destroyed by a Zeus unit to trigger this event. Upon destruction of the radar tower by any unit, the Rapiers will search for a Zeus and try to kill it.