Gamedev:UnitsOfMeasurement

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Units of Measurement

Overview

This page is copied from the CA wiki. It is a list of the many and varied units of measurement Spring Game developers have to deal with. Fortunately, all of the COB based units can be ignored if you are using LUS.

Base Units

Time

  • Seconds (s)
  • Frames (f) - There are 30 frames in a second.
  • Resource Frames - These occur every 32 frames.
  • SlowUpdate - These occur every 16 frames.

Linear

  • Elmo - Fundamental linear unit of Spring.
  • Footprint Unit - This is equal to 16 elmos. Note that in Upspring or when building a unit in game you actually see two squares per side on a footprint square. Used in UnitDef and FeatureDef footPrint{X,Z} tags. (See Gamedev:UnitDefs and Gamedev:FeatureDefs)
  • COB linear unit (clu) - 1 clu is 1/216 elmo. Scriptor can automatically converts to COB units based on a constant that you set (default: 2.5 elmos).
  • Map Size - This appears to be 512 elmos; thus a 16x16 map is about 8192 elmos on a side.

Angular

  • Degrees
  • COB angular unit (cau) - There are 65536 cau in a circle, which means there are 182.044... cau per degree. Scriptor automatically converts to cau based on a constant that you set (default converts from degrees).
  • 1/45055 circle - Used for accuracy and sprayAngle (see Gamedev:WeaponDefs).
  • Radians (rad) - There are 2 * pi radians in a circle. Used in lua.

Derived Units

Velocity, Acceleration

  • Elmo / Second (elmo/s) - Used for weapon velocity.
  • Elmo / Second2 (elmo/s2) - Used for weapon acceleration, map gravity. "Default" gravity is 130.
  • Elmo / Frame (elmo/f) - Used for unit velocity.
  • Elmo / Frame2 (elmo/f2) - Used for unit acceleration.
  • COB linear units / Second (clu/s) - Used for COB move statement speed. Always positive even if the movement is in a negative direction.

Angular Velocity, Angular Acceleration

  • COB angular units/Second (cau/s) - Used for weapon turn rate; COB turn and spin speed. Always positive even if the movement is in a negative direction.
  • COB angular units/ Frame (cau/f) - Used for unit turn rate. (Actually uses 65535 in a circle instead of 65536, but that's not enough to matter in most cases.)
  • COB angular units/ Frame-Second (cau/(f*s)) - Used for COB spin acceleration. Note that COB acceleration is signed, unlike COB speed; if you want a negative spin, you need negative acceleration.

Coordinates System

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