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OpenTS Manual

ROT

The rate an object's body and turret turn at, or the rate a homing projectile steers at.

Object rate of turn

Specification — Object rate of turn
Applies to
AircraftTypeBuildingTypeInfantryTypeUnitType
File
rules.ini
Section
[<ObjectType ID>]
Value
integer
When omitted
0

ROT is how far an object’s facing turns each game frame, in 256ths of a full circle. Values above 127 count as 127. No facing turns through more than a half circle, so the longest turn takes 128 divided by ROT frames, rounded down. At ROT=5, the example below turns to face the opposite way in 25 frames.

rules.ini
[MYDROP] ; an AircraftType registered in [AircraftTypes]
ROT=5

Vehicles and aircraft turn both their body and their turret at this rate. A structure turns its turret at it. A hover vehicle’s direction of travel swings at twice the rate, still capped at 127. An object with the jumpjet locomotor turns its body in flight at TurnRate from [JumpjetControls] instead.

ROT=0 means the facing never turns gradually: it points in each new direction the moment it is given one. Values from -1 to -128 do the same. Lower values wrap around, and some of them produce an ordinary turning rate.

An infantryman with the walk locomotor turns to each new facing at once, whatever ROT says. ROT matters only for an InfantryType whose Locomotor turns gradually. Such an infantryman starts at the maximum rate of 127, which completes any turn within one frame. It switches to its type’s ROT once a healing weapon hits it or a repair structure services it.

A LimpetFactor warhead slows the vehicle it hits but not its turning, which stays at its type’s ROT.

Projectile rate of turn

Specification — Projectile rate of turn
Applies to
BulletType
File
rules.ini
Section
[<ObjectType ID>]
Value
integer
When omitted
0

Any figure above 0 makes the projectile a homing one. A homing projectile steers toward its target and over terrain in the way. A projectile at 0 follows the path it was launched on until it hits something. Steered flight describes the homing flight model.

The figure is how far the projectile may turn in one game frame, in 256ths of a full turn. The turn is not constant: MissileROTVar swings it above the written figure so that missiles weave, and a projectile within a cell of its target turns half again as fast. A newly fired projectile turns only slightly until it has accelerated to its speed. Steered flight describes this launch phase and the fast shots that skip it.

Homing also changes the launch:

  • The shot leaves in the direction the firer faces, such as its turret’s facing, instead of being aimed at the target.
  • The projectile accelerates to the weapon’s Speed as written. A weapon whose projectile has ROT=0 has that speed replaced by one worked out from its Range.

Aircraft treat two figures specially:

  • At ROT=0, the shot leaves level along the aircraft’s heading at the aircraft’s current speed.
  • At ROT=1, the aircraft aims the shot straight at its target and launches it at the speed of the aircraft’s primary weapon.

An aircraft makes strafing runs only when the projectile of its first weapon has a ROT of 1 or less.