public override void CollectObservations()
{
GameObject onCollisionCourse;
List <GameObject> currentHazards;
List <GameObject> observedHazards = new List <GameObject>();
//First we need to factor in our position relative to the boundaries (normalize to between -1 and 1)
AddVectorObs(CalcRelPos(this.transform.position.x, boundary.xMin, boundary.xMax));
AddVectorObs(CalcRelPos(this.transform.position.z, boundary.zMin, boundary.zMax));
//The game controller has been modified to keep a list of current hazards - but needs to clear destroyed ones
gController.TidyUpHazardList();
currentHazards = gController.CurrentHazards;
//The number of objects and their relative position we observe dictates the number of vectors (which is limited)
//The observed hazards should be those closest to the agent.
observedHazards = SelectClosest(currentHazards, numHazardsObserved);
observedHazards.ForEach(AddHazardVectors);
//Fill up unused observation vectors. Using 1 instead of 0, to reflect the hazard being far away (instead of close)
for (int i = 0; i < numHazardsObserved - observedHazards.Count; i++)
{
AddVectorObs(1);
AddVectorObs(1);
}
//since the AI can only see a certain number of hazards it's fair to give a collision warning & distance
if (rBody == null)
{
AddVectorObs(0);
}
else
{
// First sort hazards by their z position (descending because smaller means closer)
currentHazards.Sort((a, b) => {
if (a.transform.position.z > b.transform.position.z)
{
return(1);
}
else
{
return(-1);
}
});
//Find the object which is in front of the ship and on a similar x coordinate
onCollisionCourse = currentHazards.Find(h => h.transform.position.z > rBody.transform.position.z &&
h.transform.position.x > rBody.transform.position.x - 0.5f &&
h.transform.position.x < rBody.transform.position.x + 0.5f);
//Add it's distance as an observation vector
if (onCollisionCourse == null)
{
AddVectorObs(-1);
}
else
{
AddVectorObs(Vector3.Distance(rBody.transform.position, onCollisionCourse.transform.position) / (Math.Abs(boundary.zMin) + boundary.zMax));
//Here's a litte danger zone bonus, to make the AI less defencive and boring
AddReward(0.01f);
}
}
}
