I would like to create my own file format, which is text based, which is imported by the editor and then made available to the runtime player as an prefab object.
I other words, I would like to mimic what happens with fbx. The editor reads it, shows any editable properties in the project window, it becomes part of the build, and then the player can instantiate a copy of it at runtime.
Is it reasonable to think I can do this with the current C# API?
I know I can load a txt extension as a TextAsset, and then process it at runtime. But I'm burning cycles at runtime and I would rather the importer did most of the processing.
Answer by GlitchEnzo2
Dec 06, 2010 at 06:48 PM
I know this is kind of old, but it really bugs me that the only answers here are to use TextAssets which you then parse at runtime.
The correct answer is to create an AssetPostprocessor and override the OnPostprocessAllAssets method. Like so:
public class CustomPostprocessor : AssetPostprocessor
/// Handles when ANY asset is imported, deleted, or moved. Each parameter is the full path of the asset, including filename and extension.
/// <param name="importedAssets">The array of assets that were imported.</param>
/// <param name="deletedAssets">The array of assets that were deleted.</param>
/// <param name="movedAssets">The array of assets that were moved. These are the new file paths.</param>
/// <param name="movedFromPath">The array of assets that were moved. These are the old file paths.</param>
private static void OnPostprocessAllAssets(string importedAssets, string deletedAssets, string movedAssets, string movedFromPath)
foreach(string asset in importedAssets)
Debug.Log("Imported: " + asset);
foreach (string asset in deletedAssets)
Debug.Log("Deleted: " + asset);
for (int i = 0; i < movedAssets.Length; i++ )
Debug.Log("Moved: from " + movedFromPath[i] + " to " + movedAssets[i]);
Then you can use the standard Mono libraries to parse the files and do whatever you want in Unity.
Do you have an example of the code that actually imports something in OnPostprocessAllAssets()? I'm trying to create a GameObject and save it as asset with AssetDatabase.CreateAsset(go,path+".asset"); but the result seems broken somehow (unity crashes eventually). Also, the GameObject immediately appears in the current scene, which is not my intention...
After some more research: is is possible to process custom files in OnPostprocessAllAssets() and create assets but impossible to create prefabs with hierarchy of game objects. That's because it's impossible to create a GameObject suitable for storing in a prefab (like OnPostprocessModel() receives) on your own.
Answer by Lucas Meijer 1
May 22, 2010 at 10:31 PM
I have never tried this, but you could give this a shot:
Make your file be imported as a textfile. Write an AssetPostProcessor, and in that do the parsing of the text, create a bunch of new objects (texture2d, material, custom scriptableobjects, AnimationClips, whatever), and use AssetDatabase.AddObjectToAsset()
to add it to the just imported file.
Again, I'm not 100% sure this will work, but it's a good first shot. Please be aware that Unity2.6.1 has a bug that makes a textasset being read as binary be garbled, so use an actual textformat, and not a binary one. I fixed this for Unity3.
Thanks for the suggestion. It gave me an error that the asset is not persistent.
OnPostprocessModel is almost working. When I get this event for the FBX import, I load the associated text file. I can then create additional GameObjects...
GameObject newgo = new GameObject( name ); newgo.transform.parent = go.transform;
I then create a mesh based on the text file...
Mesh mesh = new Mesh(); ...populate mesh... newgo.AddComponent< MeshFilter >().sharedMesh = mesh;
At runtime, I see the new GameObject with a MeshFilter, but the mesh is missing. Any ideas what is wrong?
Answer by qJake
May 21, 2010 at 10:15 PM
You can't create your own file formats that Unity imports, as far as I know. Sure, you can stick whatever files you want inside your Assets folder, and you could MAYBE write an editor script to have a custom Inspector for those files, but that's unreasonable. Here's what you can do that should be relatively easy:
public TextAsset myTextFile;
Now, in that script, you'll have your text file with all its data in it. You can read how to get the data of the text file by checking out the TextAsset documentation.
Yeah, right now I'm basically doing that. But it means that all the parsing is happening at runtime, which is slow.
I would rather have the editor parse the file during import and create an object that I can then include with the build and instantiate as needed.
The documentation seems to elude to having classes that will do this, but it isn't very clear.
Parsing a file shouldn't take that long. Try timing it to see how fast it actually goes. You could also just parse it in Start() or Awake(), which is where most of your "slow code" should go anyway. You can then store references to your created objects and just pass them around as needed (which is extremely fast and efficient).
Would it be possible to run the script to parse the text file once, and save the resulting GameObjects while the editor is running the game? That way, once you stop the editor running the engine you still have your generated GameObjects that you can include with the build, and remove your TextAsset and generator script?
Answer by hunn3s
Jun 01, 2011 at 12:31 PM
Hi! I would like to import my own formats, too. These are to then emerge also in the Project folder and also the characteristics them have to point out. For example Xpresso tags or simply only dependence of each other. I have already tried with the function AssetDatabase.AddObjectToAsset () to get ahead. however unsuccessfully. Can someone help me? Thanks a lot.
Up to 2 attachments (including images) can be used with a maximum of 524.3 kB each and 1.0 MB total.
The best place to ask and answer questions about development with Unity.
To help users post good questions and use the site effectively we have posted a user guide.
If you are a new user, check out our FAQ for more information.
If you are a moderator, see our Moderator Guidelines page.
We are making improvements to UA, see the list of changes.
For troubleshooting common problems with Unity 5.x Editor (including Win 10).
Answers and Comments
2 People are following this question.
Editor Window with settings and Asset Creation
Creating an asset from script?
Custom Inspector when Selecting from Project Tree?
Converting all MA files to FBX without changing GUIDs
Custom Asset Files