Unity touches files that are not modified with explicit intent

It's hard to work with version control system like Git, because Unity constantly modifies random files here and there, provoking garbage in diffs. For example, I edit some script, and then some material is listed as unstaged. The line `second: {r:0, g: 0, b: 0, a: 0}` is changed to `second: {r: 1. g: 0.99999994, b: 0, a: 1}`. Every time different assets are touched: prefabs, scenes, materials, metas, etc.

Why? How to make Unity stop silently modify random files in background for no reason?

P.S. Authentication to forum is still broken. Please fix it.

 

Please take a look at this screenshot from SourceTree (popular Git client):

Do you know what `OutlineMaterial.mat` is? Neither do I. Because it's some stuff from our artists, no one interested in, probably except the artists themselves. Why this material is spontaneously changed after running the game in Editor or modifying some assets? How to prevent Unity from making these arbitrary changes to files I never manually edit nor even bother about their existence?

 

There's a bunch of way this happens.

One is for version upgrades. You upgrade Unity's version, they change how stuff is serialized on the back-end, and BAM, no every single time you touch an asset, it changes it's representation. This was very noticable going from 5.4 to 5.5, where every line of text in a .prefab or .unity (scene) that represented a Component attached to a GameObject changed.

A different way is the UI. The way unity's UI system works is that the different layout components sets the values of the rect transform components in their children. Which means that if you open a scene on a different resolution than the last time, lucky you, all of the rect transforms show up changed in the git log.

Finally it's what you have - the same value changing on a single object. That usually means that some script is changing the object at edit time - either because of ExecuteInEditMode or something. It's really, really hard to track down why the value is changing, since there's no way to attach logging or a debugger. the best bet is probably to delete the material, run the game, and see what nullrefs.

 

I've noticed that for me it happens when
- modify material settings (color) using script in playmode (not in any editor scripts)
- then when you hit save scene after stopped playmode, .mat in project folder appears as changed..

*that material is referenced in script field from project folder, skybox mat in my case..

 

C# can't store exact values of certain floating point numbers, because of how C# stores them, so X.0f often gets turned into values like you saw 0.99999994f. So you'll see the value change to that. And yeah, if you change a material in code while running in the editor, that will touch the original material even though it doesn't change it permanently.

 

Thanks; I'm aware of floating point representation. But Editor's behavior is not consistent even in this sense.

Sounds like a bug: it's both unexpected and undesired. This change is useless, discarding doesn't breaks anything.

 

We too find this unexpected and undesired, saving runtime colour change values (which is common at runtime) seems totally wrong when the core prefab has not changed outside of runtime.

 

I am also facing this exact issues. not able to resolve it yet. any solution?

 

One year later, still have the same exact problem happening :\

 

One year later... same issue

 

This is very annoying.

One solution is not using .asset files and serializing/deserializing everything from json.

 

Nope, that's a very bad "solution".

If it's a code asset, then [NonSerialized], if it's a material, then probably the [HideInInspector] works, although I'm not sure about it and right now I'm not in the front of my Unity-dev computer.
If it's something else, write a destructor and write the dynamic parameters over with a predefined data on exit play mode. So you always will have a defined data in those parameters.

 

One thing you could do is use Sublime Merge and use Stage Lines or Stage Hunk in conjunction with Discard Hunk or Discard Lines, that prove somewhat productive for me.

 

For preventing materials assets being changed during runtime you could try this solution:
https://answers.unity.com/questions/487908/modifying-material-modifies-the-actual-mat-file.html

Maybe with the help of a script file that is applied to the gameobjects in question. Something like:

Code (CSharp):

1.     private void Start()
2.     {
3. #if UNITY_EDITOR
4.         Renderer r = GetComponent<Renderer>();
5.         r.sharedMaterial = new Material(r.sharedMaterial);
6. #endif
7.     }

Cheers and good luck

 

I found that by adding .gitattribute, these changes that are generated by Unity will be gone. We can find some examples of .gitattribute for Unity on GitHub.

 

can you share gitattribute file?

 

https://gist.github.com/nemotoo/b8a1c3a0f1225bb9231979f389fd4f3f
It's over here. Put it under your project's home directory, and discard all the noises that Unity generated for once, we should see that these noises won't appear ever again.

 

thx, do you know how it technically works? I mean why it solves issue with numbers

 

.gitattribute is a file that is used by Git LFS, Git LFS is a tool that deals with large files and binary files in the version control. By default, the version control system treats binary files as if they are normal text files, which is very inefficient.
The noises that we got are mostly binary files. I don't know the actual technical detail, I got this workaround through trial and error. I guess maybe it is because Git isn't very good at handling binary, and Git LFS is designed to cope with large files and binary files specifically.

 

I found a similar issue in caused by the UI, specifically BaseShaderGUI which changes the color values of _SpecColor in the last digit every time the material is inspected in the editor. I sent a bug report for this, as it messes up version control.

Confirmed in Unity 2020.1.17f1 and Unity 2021.1.7f1