Grobots - Documentation - Physics

This page documents some of the physics of Grobots.

Units

Time: Frame

The unit of time, about 1/30 second.

Distance

The unit for distance is nameless, but one small grid square in the main view corresponds with 1 distance unit. A standard-sized robot is 1 unit in diameter.

Energy

The energy unit is also nameless. A typical robot costs 1000 energy to make.

Mass

A typical robot weighs 20 mass units.

Units of speed, acceleration, and power can be derived in the usual way.

Miscellany

• Cells over standard mass (20) take extra damage proportional to the excess mass, to compensate for the combat advantage they would otherwise have. This is ugly, and we'd prefer some other way.
• Explosions do more damage to larger targets, and to targets which are near the center of the explosion. The following equation governs explosions:

  DamageTaken = Strength / (sqrt(Strength/Mass) * 0.5 + 1) * OverlapFraction

  OverlapFraction is a number between 0 and 1.
• Engines attempt to accelerate the robot towards the velocity the programmer requests. Engines take the following power to use: acceleration*mass*max(0.05, speed)/0.2
• The seek-location primitive is merely a convenience. It is equivalent to:

  seek-location: ;x y
    position v- dup
    norm radius < if
      0 engine-power!
      2drop
    else
      engine-max-power engine-power!
      0.08 vs* rect-to-polar engine-velocity!
    then return
  

• When a robot dies, its corpse has a value of one half its biomass. Abortions leave three quarters of the biomass intact.
• Food decays at 0.1 energy per frame.
• When a robot dies, an explosion of strength 0.01 * biomass is created.