Initialization of Classes Instantiated in an Array in the Inspector

Question

I'm having some trouble with a custom inspector that I haven't been able find an answer to just yet. I have a script that takes references to multiple other GameObjects, and for each GameObject uses a custom class to store some settings for it. The setup for this is very simple. I have a DustSystem class:

 public class DustSystem : MonoBehaviour
 {
     public DustSystemSettings[] dustSystems;
 
     //Logic...
 }

and the DustSystemSettings class:

 [Serializable]
 public class DustSystemSettings
 {
     public ParticleSystem particleSystem;
     public AnimationCurve  particleVelocityCurve = AnimationCurve.Linear(0, .3f, 150, 30);
     public AnimationCurve      particleRateCurve = AnimationCurve.Linear(0, 1, 150, 60);
     public AnimationCurve pariticleLifetimeCurve = AnimationCurve.Linear(0, 12, 150, 1);
 }

This is perfectly functional, but it has one really annoying drawback. When modifying the DustSystem from the inspector, I want to be able to add and remove multiple DustSystemSettings so a single script can control and many ParticleSystems as desired. The problem comes in when increasing the size of the array from the inspector. This creates a new instance of DustSystemSettings in the array, but instead of initializing it as I've described in the class definition, it is initialized with default/empty values.

The initial AnimationCurves are fairly well tuned and very valuable for quickly setting up new ParticleSystems. Losing those initial values is not feasible.

My question is, how can I get Unity to initialize new elements in the array properly? I know I can create a custom inspector and handle the adding and removing of array elements myself, but that takes a bunch of extra code and work, and I'm relatively confident there is a better way to accomplish my goal.

Thanks for you time.

Answer 1

I've resolved this by monitoring the size of the array, then manually initialize new elements when size grows. Theres the full code for a example script. Save it to a script named ArrayTest.cs and try it in the inspector.

EDIT: Unfortunately this method doesn't work well with Undo/Redo. For example, reducing the size of the array and hitting Redo will revert the removed elements to the default values. If anyone knows a better solution, please and an answer or comment.

 using UnityEngine;
 using System;
 
 
 [Serializable]
 public class Test
     {
     public float value = 1.0f;
     public string text = "Hello Text";
     }
 
 
 public class ArrayTest : MonoBehaviour
     {
     // Using Test[] instead of List<Test> allows to specify the default size for the array.
     // Each element gets initialized properly when the object is created.
 
     public Test[] array = new Test[2];
 
     // OnValidate is called from the editor each time the component receives the values
     // for its serialized properties.
     //
     // We keep track of the array size. Whenever it gets increased we initialize the new
     // elements to the default values.
 
     bool m_firstDeserialization = true;
     int m_arrayLength = 0;
 
     void OnValidate ()
         {
         if (m_firstDeserialization)
             {
             // This is the first time the editor properties have been deserialized in the object.
             // We take the actual array size.
 
             m_arrayLength = array.Length;
             m_firstDeserialization = false;
             }
         else
             {
             // Something have changed in the object's properties. Verify whether the array size
             // has changed. If it has been expanded, initialize the new elements.
             //
             // Without this, new elements would be initialized to zero / null (first new element)
             // or to the value of the last element.
 
             if (array.Length != m_arrayLength)
                 {
                 if (array.Length > m_arrayLength)
                     {
                     for (int i = m_arrayLength; i < array.Length; i++)
                         array[i] = new Test();
                     }
 
                 m_arrayLength = array.Length;
                 }
             }
         }
     }

Initialization of Classes Instantiated in an Array in the Inspector

1 Reply

Your answer

Follow this Question

Related Questions