/// <summary>
/// Update this visualisation
/// </summary>
/// <param name="node">The node for which this is a visualisation of</param>
public void SetVisualisation(NeatNode node, bool isHidden = false)
{
netNode = node;
// Disable visual for input nodes
gameObject.SetActive(!isHidden);
}
/// <summary>
/// Randomly place a node in the middle of an existing gene
/// </summary>
private void AddMutatedNode()
{
if (genes.Count == 0)
{
return;
}
// 30 attempts to create a node
for (int i = 0; i < 30; ++i)
{
int geneId = Random.Range(0, genes.Count);
NeatGene gene = genes[geneId];
// Only add node in enabled genes
if (!gene.isEnabled)
{
continue;
}
// Add the node
NeatNode newNode = new NeatNode(nodes.Count, NeatNode.NodeType.Hidden, this);
nodes.Add(newNode);
// Disable old gene and add connected genes to new node
gene.isEnabled = false;
CreateGene(gene.fromNodeId, newNode.ID).weight = 1.0f; // Use 1.0 to avoid initial impact of adding the node
CreateGene(newNode.ID, gene.toNodeId).weight = gene.weight;
return;
}
}
/// <summary>
/// Calculate the value for this node be reading incoming connections
/// </summary>
/// <param name="network">List of all the nodes in the network</param>
/// <returns>The activated value for this node</returns>
public float CalculateValue()
{
if (type == NodeType.Input || workingValueFinal)
{
return(workingValue); // Value is set or cached for us
}
else if (workingOutValue) // Can only really return approximation (Occurs in event of loop)
{
return((float)Math.Tanh(workingValue));
}
// Haven't worked out the value yet, so need to work it out now
workingValue = 0.0f;
workingOutValue = true;
foreach (NeatGene input in inputGenes)
{
// Only considered enabled genes
if (!input.isEnabled)
{
continue;
}
NeatNode inNode = network.nodes[input.fromNodeId];
workingValue += inNode.CalculateValue() * input.weight;
}
// Pass summation through activation function and cache until net inputs
workingValue = (float)Math.Tanh(workingValue);
workingValueFinal = true;
workingOutValue = false;
return(workingValue);
}