Copy a component at runtime

Question

I need to copy a component with all its values at runtime (would save me a lot of time), but I don't know how to do that. Google only brings results where people want to copy a component in editormode, w$$anonymous$$ch is available in Unity4 anyway.

My use-case: I have several objects and I want to make them burnable. For that, I would like to copy the particle components (legacy) of my fire-prefab and add them to every object I mark as "burnable" in a script, so I can switch on the particleemitter by code if it should start burning. I could do it by hand in editor, but that's rather time-consuming. So, is there a way to do that easily by code?

Answer 1

Answer by Shaffe · Dec 04, 2013 at 12:22 PM

Sometimes a prefab is not suitable.

T$$anonymous$$s method allows to copy fields values on a new component using the reflection API.

 Component CopyComponent(Component original, GameObject destination)
 {
     System.Type type = original.GetType();
     Component copy = destination.AddComponent(type);
     // Copied fields can be restricted with BindingFlags
     System.Reflection.FieldInfo[] fields = type.GetFields(); 
     foreach (System.Reflection.FieldInfo field in fields)
     {
        field.SetValue(copy, field.GetValue(original));
     }
     return copy;
 }

And here the version with generic typing:

 T CopyComponent<T>(T original, GameObject destination) where T : Component
 {
     System.Type type = original.GetType();
     Component copy = destination.AddComponent(type);
     System.Reflection.FieldInfo[] fields = type.GetFields();
     foreach (System.Reflection.FieldInfo field in fields)
     {
         field.SetValue(copy, field.GetValue(original));
     }
     return copy as T;
 }

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DAVco · Aug 21, 2014 at 03:58 PM 0

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I was able to use your generic version quite successfully, with the addition of the BindingFlags bitmask to the getFields function ( GetFields(BindingFlags.Public | BindingFlags.Instance | BindingFlags.NonPublic) )

However, this only seems to work for components created in the project - not for build in components such as BoxCollider. Any ideas on how we can improve the method to also handle these components?

ShawnFeatherly · Mar 18, 2015 at 12:23 AM 1

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The answer here handles built-in components: http://answers.unity3d.com/questions/530178/how-to-get-a-component-from-an-object-and-add-it-t.html

rolfewiz · Sep 17, 2015 at 05:32 PM 1

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@DAVco I think you need to add BindingFlags.FlattenHierarchy to get fields from inherited types.

zombience · Dec 29, 2015 at 03:32 AM 0

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thanks for this! had an odd case where prefabs weren't appropriate and needed to verify that an artist had correct components configured properly.

Thanks!

krisventure · Oct 20, 2016 at 03:01 PM 0

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This didn't work for ParticleSystemRenderer component (so I guess for any ParticleSystem**** components). I know it's a bit different in nature but Unity 5 has made many particle system properties independent 'components' which were earlier accessible from ParticleSystem component, now you need to call eg. GetComponent< ParticleSystemRenderer >(). property. Interesting however, that the version of @vladipus works for these components too (throws an error message but seem to finish copying all properties).

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Answer 2

Answer by turbanov · Dec 28, 2015 at 02:46 PM

I've edited the Shaffe's version to utilize properties and check for static variables, component reuse instead of creating new. I'm currently using t$$anonymous$$s technique in the editor, however.

     T CopyComponent<T>(T original, GameObject destination) where T : Component
     {
         System.Type type = original.GetType();
         var dst = destination.GetComponent(type) as T;
         if (!dst) dst = destination.AddComponent(type) as T;
         var fields = type.GetFields();
         foreach (var field in fields)
         {
             if (field.IsStatic) continue;
             field.SetValue(dst, field.GetValue(original));
         }
         var props = type.GetProperties();
         foreach (var prop in props)
         {
             if (!prop.CanWrite || !prop.CanWrite || prop.Name == "name") continue;
             prop.SetValue(dst, prop.GetValue(original, null), null);
         }
         return dst as T;
     }

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krisventure · Oct 20, 2016 at 03:37 PM 2

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Only this solution worked for ParticleSystemRenderer component in Unity 5!

In editor mode it gives a warning when it copies any material property that this can result in memory leaks and copying sharedMaterial is sufficient. So for that one can replace line 15 to :

 if (!prop.CanWrite || !prop.CanWrite || prop.Name == "name" || prop.PropertyType.Equals(typeof(Material)) || prop.PropertyType.Equals(typeof(Material[]))) continue;

and we can just set manually after calling your function:

 sourceComp.material = targetComp.sharedMaterial;
 sourceComp.materials = targetComp.sharedMaterials;

or just place the replacement code inside your loop.

CoughE · Feb 28, 2019 at 09:27 PM 0

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For copying an audiosource in unity 2018.3, I got the error minVolume is not supported anymore. Use min-, maxDistance and rolloffMode instead. Which I reconciled via this link. So just add

  if(!propertyInfo.IsDefined(typeof(ObsoleteAttribute), true))
      propertyValue = propertyInfo.GetValue(myComponent,null);

Answer 3

Answer by Bunny83 · May 17, 2013 at 11:30 AM

You should create a prefab of your particle effect and simply Instantiate it at runtime and attach it as c$$anonymous$$ld object.

Components are always bound to the GameObject they're attached to. The only way is to create the same component on your target GameObject and copy all variables manually. Note: t$$anonymous$$s doesn't work with all components because some have internal variables w$$anonymous$$ch you can't access from outside.

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Asvaronn · May 17, 2013 at 01:02 PM 0

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I would of course do that if I would not like to have it as a mesh particle emitter... which requires me to add the components to the object that should emit the particles. And it is not only this case. It's not the first time that I wish I could copy a component with all it's values, it would just be very useful ;)

Answer 4

Answer by wa1bo · Nov 22, 2014 at 02:36 PM

For editor only scripts, you can use: EditorUtility.CopySerialized

For runtime, you can use SerializedObject.CopyFromSerializedProperty (iterate on the properties, and applying each one)

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henrimh · Nov 13, 2017 at 01:34 PM 0

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Saved my day that EditorUtility.CopySerialized

Didn't come across that in Unity Manual or Google searches.

mtschoen · Sep 29, 2022 at 04:43 AM 0

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Unfortunately, SerializedObject is not available at runtime.

Answer 5

Answer by SuperSboy · Apr 18, 2017 at 09:15 AM

UnityEditorInternal.ComponentUtility.CopyComponent(original); UnityEditorInternal.ComponentUtility.PasteComponentAsNew(destinationObject);

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NeatWolf · Aug 26, 2020 at 10:31 AM 2

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Yes but, I don't think it works at runtime? ^__^"

Copy a component at runtime

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