Implement a graph tool

Create and implement a graph tool to visualize and manage complex data structures in Unity.

Prerequisites

Set up the code structure

Define a custom Graph class

The foundation of any Graph Toolkit tool is a custom Graph class. To create one, do the following:

1. Create a new C# script file.

2. Import the necessary namespaces:

   using System;
   using UnityEditor;
   using UnityEngine;
   using Unity.GraphToolkit.Editor;
   

3. Define a class that inherits from Graph.

4. Define an AssetExtension string constant to specify your graph’s file extension.

5. Apply the [Graph] attribute, and pass your extension as a parameter.

6. Mark your class with [Serializable] to ensure proper data persistence as you extend your graph tool.

7. Add a new CreateAssetFile function that calls the PromptInProjectBrowserToCreateNewAsset method, and decorate this function with a MenuItem attribute.

   [Graph(AssetExtension)]
   [Serializable]
   class MySimpleGraph : Graph
   {
       public const string AssetExtension = "simpleg";
   
       [MenuItem("Assets/Create/Graph Toolkit Samples/Simple Graph", false)]
       static void CreateAssetFile()
       {
           GraphDatabase.PromptInProjectBrowserToCreateNewAsset<MySimpleGraph>();
       }
   }
   

   This basic implementation creates the core structure for your graph tool. The AssetExtension constant defines the file format Unity uses to save your graph assets.

8. Create a new graph asset directly from the Unity Editor’s menu. For example, navigate to Assets > Create > Graph Toolkit Samples > Simple Graph. The new asset appears in the Assets section of the Project window with its name ready for you to enter.

9. Name the asset.

10. Double-click the graph asset file. The Graph window opens with an empty canvas.

Additional resources

• Set up the code structure
• Graph window reference