public void LoadSources()
        {
                        #if UNITY_EDITOR
            if (!UnityEditor.AssetDatabase.Contains(texArr))
            {
                Debug.Log("Texture Array is not an asset: could not get source tex"); return;
            }

            string[] sourceGuids = texArr.GetUserData("TexArr_sourceLayers");
            string[] alphaGuids  = texArr.GetUserData("TexArr_alphaLayers");

            if (sourceGuids.Length != texArr.depth || alphaGuids.Length != texArr.depth)
            {
                //throw new System.Exception("Source GUIDs array length is not equal to TexArr depth");
                sourceGuids = new string[texArr.depth];
                alphaGuids  = new string[texArr.depth];
            }

            srcArr = new SrcLayer[texArr.depth];

            for (int i = 0; i < sourceGuids.Length; i++)
            {
                if (sourceGuids[i] == null || sourceGuids[i].Length == 0)
                {
                    continue;
                }
                srcArr[i].source = sourceGuids[i].GUIDtoObj <Texture2D>();

                if (alphaGuids[i] == null || alphaGuids[i].Length == 0)
                {
                    continue;
                }
                srcArr[i].alpha = alphaGuids[i].GUIDtoObj <Texture2D>();
            }
                        #endif
        }