Unity3DでProjectビューで選択したフォルダ以下の2DテクスチャのGenerateMipmapsを全部外すエディタ拡張

ChangeTextureImportSettings

using UnityEngine;
using UnityEditor;

public class ChangeTextureImportSettings : MonoBehaviour {

    [MenuItem("Custom/Texture/CheckOffGenerateMipmaps")]
    static void CheckOffGenerateMipmaps()
    {
        Object[] textures = Selection.GetFiltered(typeof(Texture2D), SelectionMode.DeepAssets | SelectionMode.Assets);
        foreach (Texture2D texture in textures)
        {
            string path = AssetDatabase.GetAssetPath(texture);
            TextureImporter texImporter = AssetImporter.GetAtPath(path) as TextureImporter;
            if (texImporter.mipmapEnabled)
            {
                texImporter.mipmapEnabled = false;
                AssetDatabase.ImportAsset(path);
            }
        }
    }
}