/// <inheritdoc />
protected override Node AddOneNodeToTreeAtPosition(Vector3 position)
{
var closestNode = Config.Tree.GetClosestNode(position);
var direction = position - closestNode.Position;
var directionMagnitude = direction.magnitude;
if (directionMagnitude == 0) //the random point already exists in the tree, hence don't add a new one
{
return(null);
}
var lengthMultiplier = Config.MAXBranchLength < directionMagnitude
? Config.MAXBranchLength
: directionMagnitude;
var newNode = new Node(closestNode.Position + direction / directionMagnitude * lengthMultiplier);
if (IsNotCollidingWithObstacle(closestNode.Position, direction, lengthMultiplier))
{
var minNode = closestNode;
var minCost = minNode.Cost + (newNode.Position - minNode.Position).magnitude;
var neighbourNodes = Tree.GetNeighboursInRadius(newNode, _radius);
// Find closest parent cost wise (within the given radius around the new node).
// The current minNode which is closest to the newNode might not be the shortest path to reach the new node from the start node, considering the path cost.
// Hence the new node is added as child to the neighbour node which offers the shortest possible path to the new node, starting from the root node.
foreach (var n in neighbourNodes)
{
var dir = newNode.Position - n.Position;
var dirMagnitude = dir.magnitude;
if (n.Cost + dirMagnitude < minCost && IsNotCollidingWithObstacle(n.Position, dir, dirMagnitude))
{
minNode = n;
minCost = n.Cost + dirMagnitude;
}
}
Tree.AddChildNodeToParentNodeWithCost(minNode, newNode);
// Check if neighbours cost might be lower traversing through the new node, if so restructure the tree, by making the neighbour node a child of the new node.
foreach (var node in
from n in neighbourNodes
let dir = n.Position - newNode.Position
let dirMagnitude = dir.magnitude
where newNode.Cost + dirMagnitude < n.Cost &&
IsNotCollidingWithObstacle(newNode.Position, dir, dirMagnitude)
select n)
{
// make the neighbour node child of the new node
node.Parent.RemoveChild(node);
Tree.AddChildNodeToParentNodeWithCost(newNode, node);
}
var dir2 = newNode.Position - minNode.Position;
if (IsCollidingWithTarget(minNode.Position, dir2, dir2.magnitude) && !Tree.HasFoundPath)
{
Debug.Log("Found Path");
Tree.TargetNode = newNode.Position == PosTarget ? newNode : AddOneNodeToTreeAtPosition(PosTarget);
}
return(newNode);
}
return(null);
}
