Fbx Attributes

Small utility scripts to easily extract attributes from FBX file meshes and get them into unity.
This allow you to set up a scriptable object that will automatically receive the attributes of an FBX mesh.

 

Application

I use this technique in a procedural generation.
The parts of the castle are from KattyLi's 3D model on sketchfab

The terrain above is procedurally generated using the tiles below. I created these tiles in Maya and put attributes on them with information allowing the generation algorithm to place them in the right place.




The creation time is greatly optimized. After I finished my export from Maya, a simple focus on the Unity application triggers the reimport of the model, its attributes and restarts the generation of the terrain. I can then directly see the result of my modification / new part.

 

Usage

⚠️This project requires the FBX Exporter package

(Official Unity package available in the Unity Registry from the Package Manager tool in Unity).

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The whole thing is quite simple to use. An example is available in the project.

To use the project, you have to make two scripts:

• The first one will contain the attribute data. It must have the [System.Serializable] attribute and implement the IMeshAttributes interface. Then, put the variables you want to extract from the FBX file.

//Simplified example on purpose - See the FbxMeshExample.cs script for more details
using UnityEngine;

[System.Serializable]
public class MyFbxMeshAttributes : IMeshAttributes
{
    //Required data 
    public Mesh mesh { get; set; }
    public string[] materials { get; set; }

    //Attributes that will be read from the fbx file
    public MyEnum myEnum;
    public string myString;
    public int myInteger;
    public float myFloat;
    public Color myColor;
    public Vector3 myVector;
}

 

• The second class is the scriptable object which will contain a list of instances of the previous class and will be automatically generated. It must have the attribute FbxAttribute(string filenameFilter) and inherit from FbxScriptableObject<MyFbxMeshAttributes>.

[FbxAttribute("Tile", suffix = "_Attributes")]
public class MyFbxObject : FbxScriptableObject<MyFbxMeshAttributes>
{
}

The filenameFilter is used to indicate which objects should have a postImport on them. Only objects containing the filter will be processed. You can use regex functions.

The suffix is optional, it is used to add a suffix to the generated file, this can easily avoid clashes.

 

 

In your second script. You can access the data with the variable childs.

You can also override the OnPostImport() function which is called after each update of the object.

[FbxAttribute("Tile", suffix = "_Attributes")]
public class MyFbxObject : FbxScriptableObject<MyFbxMeshAttributes>
{
    public void LogAllChildsNameAndColor()
    {
        foreach (var child in childs)
        {
            Debug.Log($"Mesh {child.mesh.name} is {child.myColor}");
        }
    }

    public override void OnPostImport()
    {
        Debug.Log("This object has just been updated");
    }
}

 

Maya helpers

Setting attributes on Maya is sometimes a bit painful, the interface does not allow to create all types and the setup can be long.
So I created a new shelf that you can get in
Maya\self_Attributes
and copy in your folder :
C:\Users\[UserName]\Documents\maya[Version]\prefs\shelves\

This allows you to create attributes more quickly and copy them from one object to another.