Model groups.

Added model group support, you can now have multiple meshes in one export.
Removed OBJ and mesh replace export options.
Mesh replace didn't work, might get added again in the feature.
OBJ needs to be rewritten as well to support the multiple meshes, and Unity now has model export options in engine.
Version 1.8.0+ is now only supports Unity2018.3+.

Assets/MA_ToolBox/MA_TextureAtlasserPro/Scripts/Data/MA_ModelGroup.cs

@@ -0,0 +1,15 @@
+#if UNITY_EDITOR
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+namespace MA_TextureAtlasserPro
+{
+    [System.Serializable]
+    public class MA_ModelGroup
+    {
+        public string name = "Model";
+        public List<Mesh> meshes = new List<Mesh>();
+    }
+}
+#endif

Assets/MA_ToolBox/MA_TextureAtlasserPro/Scripts/Data/MA_ModelGroup.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 1f74ddc7d8c9c30429ec163b4fc801c4
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/MA_ToolBox/MA_TextureAtlasserPro/Scripts/Data/MA_TextureAtlasserProAtlas.cs

@@ -15,7 +15,7 @@ namespace MA_TextureAtlasserPro
 		public List<MA_TextureAtlasserProQuad> textureQuads;
 		public MA_TextureAtlasserProQuad selectedTextureQuad;
 		private Rect editorWorkRect;
-		public bool showTextures = false;
+		public bool showTextures = true;
         public MA_TextureAtlasserProExportSettings exportSettings;
 
 		//Data

Assets/MA_ToolBox/MA_TextureAtlasserPro/Scripts/Data/MA_TextureAtlasserProExportSettings.cs

@@ -50,9 +50,7 @@ namespace MA_TextureAtlasserPro
     public enum ModelFormat
     {
         None,
-        UnityMeshPrefab,
-        ReplaceMesh,
-        Obj
+        UnityMeshPrefab
     }
 
     public enum TextureFormat

Assets/MA_ToolBox/MA_TextureAtlasserPro/Scripts/Data/MA_TextureAtlasserProQuad.cs

@@ -11,22 +11,28 @@ namespace MA_TextureAtlasserPro
 	public class MA_TextureAtlasserProQuad : ScriptableObject
 	{
 		//Editor
-		public bool isSelected = false;				//Is this thing selected
-		public Rect rect;							//The internal rect
-		public Rect guiRect;						//The visual clamped and snapped rect
-		public bool debugMode = false;				//Are we debugging, for showing some other things (like handles)
+		[HideInInspector]
+		public bool isSelected = false;             //Is this thing selected
+		public Rect rect;                           //The internal rect
+		[HideInInspector]
+		public Rect guiRect;                        //The visual clamped and snapped rect
+		[HideInInspector]
+		public bool debugMode = false;              //Are we debugging, for showing some other things (like handles)
 
-		private bool isDragging = false;			//Are we editing the pos or size
+		private bool isDragging = false;            //Are we editing the pos or size
 		private bool isDraggingRectHeigt = false;
+		[HideInInspector]
 		public Rect dragRectHeight;
 		private bool isDraggingRectWidth = false;
+		[HideInInspector]
 		public Rect dragRectWidth;
 		private bool isDraggingRectPos = false;
+		[HideInInspector]
 		public Rect dragRectPos;
 
 		//Data
 		public List<MA_TextureGroup> textureGroups;
-		public List<Mesh> meshes;
+		public List<MA_ModelGroup> modelGroups;
 
 		public void UpdateTextureQuad(Event e, Rect editorViewRect, Rect editorWorkRect, Vector2 zoomCoordsOrigin, bool useEvents, bool showTexture)
 		{

Assets/MA_ToolBox/MA_TextureAtlasserPro/Scripts/Data/MA_TextureAtlasserProSettings.cs

@@ -23,7 +23,6 @@ namespace MA_TextureAtlasserPro
 		public KeyCode zoomOutHotKey = KeyCode.Minus;
 
 		[Header("Duplication:")]
-		public bool copySelectedQuadData = true;
 		public string duplicatedQuadNamePrefix = "new ";
 
 		[Header("Selection")]