diff --git a/OpenRa.FileFormats/Map.cs b/OpenRa.FileFormats/Map.cs
index 19e887ae61..b5704ac475 100644
--- a/OpenRa.FileFormats/Map.cs
+++ b/OpenRa.FileFormats/Map.cs
@@ -104,8 +104,14 @@ namespace OpenRa.FileFormats
 			}
 
 			for( int i = 0 ; i < 128 ; i++ )
+			{
 				for( int j = 0 ; j < 128 ; j++ )
+				{
 					MapTiles[ j, i ].image = ReadByte( ms );
+					if( MapTiles[ j, i ].tile == 0xff || MapTiles[ j, i ].tile == 0xffff )
+						MapTiles[ j, i ].image = (byte)( i % 4 + ( j % 4 ) * 4 );
+				}
+			}
 		}
 
 		void ReadTrees( IniFile file )
diff --git a/OpenRa.Game/Actor.cs b/OpenRa.Game/Actor.cs
index 0b8ed203ef..397dc37553 100644
--- a/OpenRa.Game/Actor.cs
+++ b/OpenRa.Game/Actor.cs
@@ -8,9 +8,9 @@ using System.Windows.Forms;
 
 namespace OpenRa.Game
 {
-	class Actor
+	abstract class Actor
 	{
 		public PointF location;
-		public SheetRectangle<Sheet>[] currentImages;
+		public abstract SheetRectangle<Sheet>[] CurrentImages { get; }
 	}
 }
diff --git a/OpenRa.Game/MainWindow.cs b/OpenRa.Game/MainWindow.cs
index e2e991a18e..8820b6c46b 100644
--- a/OpenRa.Game/MainWindow.cs
+++ b/OpenRa.Game/MainWindow.cs
@@ -72,6 +72,9 @@ namespace OpenRa.Game
 
 			foreach (TreeReference treeReference in map.Trees)
 				world.Add(new Tree(treeReference, treeCache, map));
+
+			UnitSheetBuilder.AddUnit( "mcv", renderer.Device, pal );
+			world.Add( new Mcv( new PointF( 24 * 5, 24 * 5 ) ) );
 		}
 
 		void LoadVertexBuffer()
diff --git a/OpenRa.Game/Mcv.cs b/OpenRa.Game/Mcv.cs
index 65f914e75f..1d7d533a1b 100644
--- a/OpenRa.Game/Mcv.cs
+++ b/OpenRa.Game/Mcv.cs
@@ -2,18 +2,22 @@ using System;
 using System.Collections.Generic;
 using System.Text;
 using OpenRa.FileFormats;
+using System.Drawing;
 
 namespace OpenRa.Game
 {
 	class Mcv : Actor
 	{
-		int facing;
+		//int facing; // not currently used
 
-		static Package unitsPackage = new Package("../../../conquer.mix");
-
-		public Mcv()
+		public Mcv( PointF location )
 		{
+			this.location = location;
+		}
 
+		public override SheetRectangle<Sheet>[] CurrentImages
+		{
+			get { return new SheetRectangle<Sheet>[] { UnitSheetBuilder.McvSheet[ 0 ] }; }
 		}
 	}
 }
diff --git a/OpenRa.Game/OpenRa.Game.csproj b/OpenRa.Game/OpenRa.Game.csproj
index cddbae16fe..e7f15c90ef 100644
--- a/OpenRa.Game/OpenRa.Game.csproj
+++ b/OpenRa.Game/OpenRa.Game.csproj
@@ -52,6 +52,7 @@
     <Compile Include="Sheet.cs" />
     <Compile Include="Tree.cs" />
     <Compile Include="TreeCache.cs" />
+    <Compile Include="UnitSheetBuilder.cs" />
     <Compile Include="Util.cs" />
     <Compile Include="Vertex.cs" />
     <Compile Include="World.cs" />
diff --git a/OpenRa.Game/Program.cs b/OpenRa.Game/Program.cs
index b09eca57aa..2a32eef6e5 100644
--- a/OpenRa.Game/Program.cs
+++ b/OpenRa.Game/Program.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Windows.Forms;
+using System.IO;
 
 namespace OpenRa.Game
 {
@@ -9,10 +10,18 @@ namespace OpenRa.Game
 		[STAThread]
 		static void Main()
 		{
-			Application.EnableVisualStyles();
-			Application.SetCompatibleTextRenderingDefault(false);
+			try
+			{
+				Application.EnableVisualStyles();
+				Application.SetCompatibleTextRenderingDefault( false );
 
-			new MainWindow().Run();
+				new MainWindow().Run();
+			}
+			catch( Exception e )
+			{
+				File.WriteAllText( "error.log", e.ToString() );
+				throw;
+			}
 		}
 	}
 }
\ No newline at end of file
diff --git a/OpenRa.Game/Tree.cs b/OpenRa.Game/Tree.cs
index 9228b424e5..d6e7213334 100644
--- a/OpenRa.Game/Tree.cs
+++ b/OpenRa.Game/Tree.cs
@@ -13,5 +13,11 @@ namespace OpenRa.Game
 			location = new PointF(24 * (r.X - map.XOffset), 24 * (r.Y - map.YOffset));
 			currentImages = new SheetRectangle<Sheet>[] { renderer.GetImage(r.Image) };
 		}
+
+		SheetRectangle<Sheet>[] currentImages;
+		public override SheetRectangle<Sheet>[] CurrentImages
+		{
+			get { return currentImages; }
+		}
 	}
 }
diff --git a/OpenRa.Game/UnitSheetBuilder.cs b/OpenRa.Game/UnitSheetBuilder.cs
new file mode 100644
index 0000000000..4a5b7defa8
--- /dev/null
+++ b/OpenRa.Game/UnitSheetBuilder.cs
@@ -0,0 +1,45 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using OpenRa.FileFormats;
+using System.Drawing;
+using BluntDirectX.Direct3D;
+
+namespace OpenRa.Game
+{
+	static class UnitSheetBuilder
+	{
+		static readonly Package unitsPackage = new Package( "../../../conquer.mix" );
+		public static readonly List<SheetRectangle<Sheet>> McvSheet = new List<SheetRectangle<Sheet>>();
+
+		public static void AddUnit( string name, GraphicsDevice device, Palette pal )
+		{
+			List<Sheet> sheets = new List<Sheet>();
+			Size pageSize = new Size( 1024, 512 );
+
+			Provider<Sheet> sheetProvider = delegate
+			{
+				Sheet sheet = new Sheet( new Bitmap( pageSize.Width, pageSize.Height ) );
+				sheets.Add( sheet );
+				return sheet;
+			};
+
+			TileSheetBuilder<Sheet> builder = new TileSheetBuilder<Sheet>( pageSize, sheetProvider );
+
+			ShpReader reader = new ShpReader( unitsPackage.GetContent( name + ".shp" ) );
+			foreach( ImageHeader h in reader )
+			{
+				Bitmap bitmap = BitmapBuilder.FromBytes( h.Image, reader.Width, reader.Height, pal );
+
+				SheetRectangle<Sheet> rect = builder.AddImage( bitmap.Size );
+				using( Graphics g = Graphics.FromImage( rect.sheet.bitmap ) )
+					g.DrawImage( bitmap, rect.origin );
+
+				McvSheet.Add( rect );
+			}
+
+			foreach( Sheet sheet in sheets )
+				sheet.LoadTexture( device );
+		}
+	}
+}
diff --git a/OpenRa.Game/World.cs b/OpenRa.Game/World.cs
index 2551b0cd78..1c7ff658a1 100644
--- a/OpenRa.Game/World.cs
+++ b/OpenRa.Game/World.cs
@@ -43,11 +43,20 @@ namespace OpenRa.Game
 
 			foreach (Actor a in actors)
 			{
-				if (a.currentImages == null)
+				if (a.CurrentImages == null)
 					continue;
 
-				foreach (SheetRectangle<Sheet> image in a.currentImages)
+				foreach (SheetRectangle<Sheet> image in a.CurrentImages)
 				{
+					if( image.sheet != sheet && sprites > 0 && sheet != null )
+					{
+						DrawBatch( vertices, indices, renderer, sheet );
+
+						vertices = new List<Vertex>();
+						indices = new List<ushort>();
+						sprites = 0;
+					}
+
 					sheet = image.sheet;
 					Util.CreateQuad(vertices, indices, a.location, image);