Version 0.2.0 Alpha (last updated 2010)
Authors: David Collien (wrote simulator and API), Daniel Goldbach (wrote genetic_algorithm.py)
A "humperdink" is a virtual creature simulated in a 2D physics environment.
The humperdink is parameterised as a set of limbs connected by oscillating joints.
The parameters for each limb are:
- angle (direction relative to the limb's parent)
- length
- frequency (how fast to move the limb)
- amplitude (in radians, how far to turn on an oscillation)
- phase (in modulo 2*pi, the phase shift of the sinusoid - e.g. a phase shift of pi would place the oscillation completely out of phase, turning in the opposite direction)
These parameters, and the connectivity of limbs are specified as a tree in JSON format, for example:
{
"angle":3.14,
"length":40.0,
"connections": [
{
"angle":1.57,
"length":20.0,
"frequency":3.0,
"amplitude":3.14,
"phase":2.10,
"connections": [
{
"angle":0.0,
"length":40.0,
"frequency":6.0,
"amplitude":0.4,
"phase":0.0,
"connections": []
}
]
},
{
"angle":-1.57,
"length":20.0,
"frequency":3.0,
"amplitude":3.14,
"phase":4.20,
"connections": [
{
"angle":0.0,
"length":40.0,
"frequency":6.0,
"amplitude":0.4,
"phase":0.0,
"connections": []
}
]
}
]
}
(whitespace non-essential)
Runtime Flags:
-
-f filenamespecify the JSON file to read from (without this flag it defaults to stdin) -
-i iterationsspecify the number of iterations before termination -
-s speedspecify the number of iterations to process before displaying a frame -
-gsuppress graphical output
Compilation:
run: make
Requires jansson JSON library, provided in tar.gz
Typical installation:
./configure
make
sudo make install
Compile with -DNOGRAPHICS
to make a non-graphical executable that does not require OpenGL libraries
requires Open GL and GLUT for graphical display.
on Ubuntu this may require:
sudo apt-get install libgl1-mesa-dev libglu1-mesa-dev freeglut3-dev
Nvidia hardware might prefer:
sudo apt-get install nvidia-glx-180-dev
in which case you'll need to change the Makefile's CFLAGS line to have:
-I/usr/share/doc/nvidia-glx-180-dev/include/
Compiling your program with the humperdink simulator:
The following shows a basic example:
#include "environment.h"
#include "creature.h"
#include <stdlib.h>
#include <stdio.h>
int main( int argc, char *argv[] ) {
json_t *json;
json_error_t error;
char humperdink[] = "{\"angle\":0.0,\"length\":50.0,\"connections\": []}";
// see also json_loadf and json_load_file
// http://www.digip.org/jansson/doc/dev/tutorial.html
json = json_loads( humperdink, &error );
if( !json ) {
fprintf( stderr, "Error parsing humperdink on line %d:\n", error.line );
fprintf( stderr, "\t%s\n\n", error.text );
exit( 0 );
}
Environment simulationEnvironment = createEnvironment( 800, 600 );
Creature simulatedCreature = createCreature( json, getEnvironmentSpace( simulationEnvironment ) );
int iterations = 100;
for ( int i = 0; i < iterations; ++i ) {
updateEnvironment( simulationEnvironment );
double x = getCreatureX( simulatedCreature );
double y = getCreatureY( simulatedCreature );
printf( "(%lf, %lf)\n", x, y );
}
destroyCreature( simulatedCreature );
destroyEnvironment( simulationEnvironment );
return 0;
}