Abstract
The intention of this project is to demonstrate how survival constraints shapes the species' phenotype through natural selection.
Following the model of plants, each creature needs to receive enough sunlight (energy constraint) and to grow upright (balancing constraint) in order to survive. The creatures compete for sunlight: if a create is in the shadow of another, it will only receive a small fraction of the sun's energy.
The result is the emergence of creatures with a clearly identifiable vertical stem, and a platform at the top to harness sunlight.
The program generates a few initial species with random DNA and creates a few creatures.
Each Creature is composed of several Cells.
The DNA dictates the growth direction for each Cell.
The program will launch a window that will display a 3D view of the World on the left, and the typical shape of the dominant species on the right, rotating.
Usage
Commands:
- F - Fullscreen
- S - Summary: Prints a summary of the current species (with some lineage info)
- [SPACE] - pause/resume simulation
- N - Next: when paused, runs a single cycle
- F1 - perform a consitency check on the cells (debug)
- '=' - Switches the right view to show either the biggest creature or the typical DNA creature from the current dominant species.
- [ESC]/Q - exit
Please see common.h for settings/customizations/performance.
Constraints
There are strict rules for survival:
- Sunlight constraint: the creature must gather enough energy from its cells to survive. The more cells, the more energy it needs. If a creature is in the shade of another, it will not get as much sunlight (see CONTRAINT_NEED_SUN, MIN_ENERGY_PER_CELL, SUNLIGHT_LOSS_RATIO)
- Balancing constraint: the creatures must not lean too much in one direction (see CONSTRAINT_BALANCING, BALANCING_THRESHOLD)
- Other constraints exist about the age of a creature and its ability to grow (see MAX_CREATURE_AGE, GROW_OR_DIE)
Reproduction
(see REPRODUCTION_RATE)
A recent addition has been to make a new creature appear close to its parent (see LOCALITY_ENABLED, LOCALITY_RADIUS). This creates patches of colors corresponding to competing territories of species.
Mutations
(see MUTATION_RATE)
One of the DNA segment that dictates the direction of growth of a cell will be altered. The resulting species may or may not be fit for survival.
Spontaneous species
(see SPONANEOUS_SPECIES_PER_CYCLE)
Randomly sprinkle new species out of nowhere to improve competition.
Performance
You can configure the number of threads to use in common.h. I recommend to use NbCores - 1 (see NB_THREADS).
TODO
- Allow to grow from any existing cell, not only from the head (see PROGRESSIVE_DNA)
Technicalities
RULE_SEEDS_Z0:
The Z=0 plan is underground and reserved for new seeds (first cell of new creatures).
From there the creature will grow a cell at Z=1 and never come back at Z=0.
This is actually a performance improvement that greatly simplify the search for an available tile underground.
Screen Shots
