Multi tool use

Unity serialized objects in different Lists not equal after pressing Play

basicly I have these lists:

[System.Serializable]
public class PatrolGraph : MonoBehaviour {

public List<Node> nodes = new List<Node>();
public List<Edge> edges = new List<Edge>();
[...]
}


I generate both Lists (nodes and edges) using a method I run from the editor.
Node and Edge are both serializable, and Edge containes two Nodes. However, after I hit play, the Nodes saved in the Edge objects of the edges list don't seem to be the same as the Nodes in my nodes list (NodeA.Equals(NodeB)), even though they should be.
If I run the function to generate the Lists during Playmode (the same one I run in edit mode), the Equals function suddenly returns true.

Here is the code for the Node and Edge classes:

Node:

[System.Serializable]
public class Node
{
public float lastVisited = 0;
public Vector3 position;
}


Edge:

[System.Serializable]
public class Edge
{
public Node A;
public Node B;

public Edge (Node A, Node B)
{
this.A = A;
this.B = B;
}
}


I want Node A and B in the Edge objects to be the same Nodes as ones saved in the nodes list after I hit play. What am I doing wrong?

Thanks in advance

2 Answers
2

It's because Object.Equals check only reference when Edge and Node are reference types. And Serialialization create new object with new address, that's why Equals returns false. If you override this method to check values of fields it will solve your problem. I recommend to check MSDN for further information how to override Equals. Or answer on forum with unity community:

Object.Equals

Edge

Node

Equals

As mentioned by Kacper, it is not possible to save references when using serialisation. After deserialisation, The Nodes referenced in multiple variables will result in seperate instances for each variable and cause the Equals function to return false when used on those instances.

However I did manage to save the Edges between Nodes by adding ids to the Nodes, that represent their list index

for (int i = 0; i< nodes.Length; i++){
nodes[i].id = i;
}


and having the Edges just save the index/ids of the nodes instead of referencing the nodes themselves

public class Edge
{
public int id_1;
public int id_2;
}


which solved the problem.

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