How to prevent editor to set the scene dirty if a script changes a mesh (@ExecuteInEditMode)

Question

I've got a script that manages a custom mesh and needs to run in the editor. It works like intended, but changing the mesh (say by calling "GetComponent().sharedMesh.Clear()") causes the scene to set it's state to dirty (the * in the editor's titlebar shows up permanently and indicates a changed scene).

As I generate the mesh by code there's no reason for the user to save those changes, so is there a way to disable t$$anonymous$$s behavior?

T$$anonymous$$s must be possible somehow as the buildin ParticleSystem both runs in the editor and changes it's mesh without setting the scene dirty.

Update: I tried HideFlags.DontSave but without luck. As soon as I change some vertices the scene went dirty.

Update 2: Like tranquility suggested, I've tried the following:

[ExecuteInEditMode] public class Meshtest : MonoBehaviour { Mesh mMesh;

 void OnEnable () {
     mMesh = new Mesh(); // create a private mesh
 }

 void Update()
 {
         mMesh.Clear(); // scene will turn to dirty state
 }

but even without any MeshFilter and MeshRenderer present in the scene it will turn to changed state immediately.

Answer 1

Best Answer

Answer by Quazistax · May 05, 2011 at 08:13 AM

Changes to "sharedMesh" are persistent, for example, if you change it in play mode, changes will be kept after exiting play mode, scene will be changed. If you change MeshFilter's "mesh" property, changes will disappear after exiting play mode. Unfortunately, seems like you can not change "mesh" property in edit mode.

What you could do is creating one or more Mesh you want to show and use Grap$$anonymous$$cs.DrawMesh. If you want to keep "sharedMesh" intact as part of your game object, but want to $$anonymous$$de it, disable MeshRenderer component.

EDIT: I set $$anonymous$$deFlags and it worked - private mesh changes don't make scene dirty.

void OnEnable () 
    {
        mMesh = new Mesh(); // create a private mesh
        mMesh.$$anonymous$$deFlags = HideFlags.HideAndDontSave;
    }

You will get t$$anonymous$$s message, probably when saving scene: "Cleaning up leaked objects in scene since no game object, component or manager is referencing them. Mesh has been leaked # times." But it is harmless.

However, if you find a way to avoid that message, it would be nice to know how.

EDIT: Move the initialization code from OnEnable to Awake function, I don't get "leaked objects" message after that.

Add comment · Show 11 · Share

Jake-L · May 06, 2011 at 11:03 AM 0

Share

Quazistax · May 06, 2011 at 10:41 PM 0

Share

Jake-L · May 07, 2011 at 07:39 AM 0

Share

Quazistax · May 07, 2011 at 08:45 AM 0

Share

Quazistax · May 07, 2011 at 08:56 AM 0

Share

Show more comments

How to prevent editor to set the scene dirty if a script changes a mesh (@ExecuteInEditMode)

1 Reply

Your answer

Welcome to Unity Answers

Follow this Question

Related Questions