ModelPostProcessor.cs

using System;
using System.IO;
using UnityEditor;
using UnityEngine;

public class ModelPostProcessor : AssetPostprocessor
{
    public void OnPreprocessModel()
    {
        // Apple settings to all atlases

        ModelImporter importer = assetImporter as ModelImporter;
        String name = importer.assetPath.ToLower();
        if (assetPath.Contains(".blend") || assetPath.Contains(".fbx"))
        {
            //importer.globalScale = 1.0F;
            //importer.importAnimation = false;
            //importer.animationType = ModelImporterAnimationType.None;
            //importer.importBlendShapes = false;
            //importer.generateSecondaryUV = true;
            //importer.importNormals = ModelImporterNormals.Calculate;
            //importer.normalSmoothingAngle = 30;

            importer.importMaterials = false;
            //importer.materialName = ModelImporterMaterialName.BasedOnMaterialName;
            //importer.materialSearch = ModelImporterMaterialSearch.Everywhere;
        }
    }
    public Material OnAssignMaterialModel(Material material, Renderer renderer)
    {
        //if (AssetDatabase.LoadAssetAtPath(materialPath, typeof(Material)))
        //return AssetDatabase.LoadAssetAtPath(materialPath, typeof(Material));

        string matPath = string.Format("Assets/Project/Materials/{0}.mat", material.name);

        string drivePath = Path.Combine(Application.dataPath, "Project/Materials/" + material.name + ".mat");
        Log("Trying to find " + matPath + " at " + drivePath);

        bool assetExists = File.Exists(drivePath);
        if (assetExists)
        {



            // Find if there is a material at the material path
            // Turn this off to always regeneration materials
            if (AssetDatabase.LoadAssetAtPath(matPath, typeof(Material)))
                return AssetDatabase.LoadAssetAtPath(matPath, typeof(Material)) as Material;


            // Create a new material asset using the specular shader
            // but otherwise the default values from the model
            //material.shader = Shader.Find("Unlit/FoxtreeToon");
            //AssetDatabase.CreateAsset(material, "Assets/" + material.name + ".mat");
            return material;
        }
        Log("Could not find material!!!", "red");
        return AssetDatabase.LoadAssetAtPath("Assets/Project/Materials/Default.mat", typeof(Material)) as Material;
    }

    void Log(string text, string color = "grey")
    {
        Debug.Log(string.Format("<color={1}>[Material Processing] {0}</color>", text, color));
    }
}