config.yaml

dna:
  # A creature's DNA contains a fixed number of chromosomes.
  number_of_chromosomes: 16

  # During copy, a gene can mutate. The likelihood of that
  # happening is mutation_rate. If it does mutate, then the
  # gene's value is either incremented or decremented by a
  # random amount in the range [0, mutation_range].
  mutation_rate: 0.08
  mutation_range: 15.0

physics:
  # The effort of a creature moving is measured in an arbitrary
  # unit - call it a "joule". This is the amount of energy that
  # is needed for one such unit.
  energy_expense_per_joule: 0.1

  # Once a creature's tangential velocity gets over this value,
  # it starts getting impacted by viscosity - which means that
  # it will level off to its maximum value quick. This is to
  # avoid creatures getting longer and faster forever. It doesn't
  # impact rotation.
  viscosity_kickin_velocity: 300

  # A higher metabolic rate has many advantages (mainly you move
  # faster), but one disadvantage: it raises energy consumption
  # by a non-linear factor. This factor equals the metabolic
  # rate to the power of metabolic_consumption_pow.
  metabolic_consumption_pow: 1.5

  # If two objects get closer than this, then they're colliding.
  collision_distance: 60.0

creature:
  # The dish is populated with seed creatures, with an energy of
  # seed_energy. Their maximum energy is that value multiplied by
  # max_energy_to_initial_energy.
  seed_energy: 25000.0
  max_energy_to_initial_energy: 5.0

  # A creature cannot live more than max_lifespan ticks, and it
  # cannot reproduce before mature_age ticks.
  max_lifespan: 100000
  mature_age: 5000

  # The base frequency of a creature's wave.
  base_wave_frequency: 0.01

  # A creature "skews" its movements depending on the current angle
  # of the target (up to a maximum absolute angle of lateral_viewfield).
  # The skewing is not instantaneous - to change its skewing, a
  # creature has a base_skewing_velocity, that is then multiplied
  # by its metabolic rage.
  lateral_viewfield: 135.0
  base_skewing_velocity: 0.1

  # A creature will give at least this amount of energy to its
  # offspring, and refuse to reproduce if it doesn't have enough
  # energy.
  min_energy_to_children: 10000.0

organ:
  # At birth, an organ has a minimum length and thickness. Both
  # grow at growth_rate until they reach their genetically
  # determined values. (Note that the rate is not the same
  # for all organs - organs farther away from the head grow
  # faster).
  minimum_length_at_birth: 5
  minimum_thickness_at_birth: 1
  growth_rate: 0.01

egg:
  # Eggs have a radius (which is purely a graphical thing) and
  # a mass (influencing how fast they move after being "fired"
  # from a creature).
  radius: 25
  mass: 0.1

  # An egg's incubation time varies randomly in this range.
  min_incubation_time: 400
  max_incubation_time: 800

  # As a newly laid egg moves, its velocity decays: with each
  # tick, the velocity is multiplied by velocity_decay. Once
  # it gets below min_velocity, the velocity is zeroed. 
  velocity_decay: 0.98
  min_velocity: 0.1

food:
  # Food pieces have a radius (which influences collisions)
  # and provide a certain amount of energy to the creature
  # that eats them.
  radius: 7
  energy: 30000

ecosystem:
  # A "block" is a 1000x1000 square. The entire dish is a
  # square whose edges are measured in blocks. The default
  # number of blocks per edge is different in the "narjillos"
  # app (with graphics) and the "experiment" script (without
  # graphics).
  blocks_per_edge_in_app: 40
  blocks_per_edge_in_experiment: 40

  # The dish is populated with eggs and food. The density
  # of both is calculated based on the total number of blocks. 
  eggs_density_per_block: 0.18
  food_density_per_block: 0

  # Food keeps respawning with an average interval (which is
  # calculated based on a single block - so the total interval
  # is food_respawn_average_interval_per_block divided by the
  # total number of blocks). If food density ever gets over
  # a maximum (defined by max_food_density_per_1000_blocks),
  # then food stops respawning.
  food_respawn_average_interval_per_block: 800000
  max_food_density_per_1000_blocks: 0.3

  # Every update_food_targets_interval ticks, the creatures
  # get a chance to point at a new target.
  update_food_targets_interval: 1000

  # The initial level for each element (Oxygen, Hydrogen and Nitrogen)
  # in the atmosphere. Narjillos breathe by converting each element
  # into another, so the maximum theoretical level for an element is
  # three times this number, assuming that the other elements drop to
  # zero. In practice, the higher this number, the longer it takes to
  # change the composition of the atmosphere (other things being equal,
  # such as the number of Narjillos in the system). As this number grows,
  # the system becomes more "inertial", taking longer to switch, for
  # example, from an atmosphere with a prevalence of Oxygen to an
  # atmosphere with a prevalence of Hydrogen.
  initial_element_level: 1000000000

  # The amount of Catalyst in the atmosphere. The Catalyst is used by
  # the creatures to convert elements and breathe. If the Catalyst is
  # 0, then nobody can breathe.
  # The Catalyst is a constant amount - no matter how much of it the
  # Narjillos consume during one tick, it's always fully replenished
  # at every tick.
  # The total amount of Catalyst is subdivided amongst the creatures,
  # so the higher this number, the higher the number of creatures that
  # can can take full advantage of breathing. In practice, this number
  # constrains the amount of creatures that can populate the dish at
  # once.
  catalyst_level: 100

experiment:
  # Every sample_interval_ticks, an experiment reports its
  # current status on the console. Every save_interval_seconds,
  # it saves its state to an .exp file.
  sample_interval_ticks: 10000
  save_interval_seconds: 600