diff --git a/PolyVoxCore/source/SurfaceExtractors.cpp b/PolyVoxCore/source/SurfaceExtractors.cpp
index bffbb8bd..08c67878 100644
--- a/PolyVoxCore/source/SurfaceExtractors.cpp
+++ b/PolyVoxCore/source/SurfaceExtractors.cpp
@@ -29,7 +29,7 @@ namespace PolyVox
 			regionGeometry.m_patchSingleMaterial = new IndexedSurfacePatch(false);
 			regionGeometry.m_v3dRegionPosition = iterChangedRegions->getLowerCorner();
 
-			generateDecimatedMeshDataForRegion(volume.getVolumeData(), 0, *iterChangedRegions, regionGeometry.m_patchSingleMaterial);
+			generateDecimatedMeshDataForRegion(volume.getVolumeData(), 1, *iterChangedRegions, regionGeometry.m_patchSingleMaterial);
 
 			//genMultiFromSingle(regionGeometry.m_patchSingleMaterial, regionGeometry.m_patchMultiMaterial);
 
diff --git a/PolyVoxCore/source/SurfaceExtractorsDecimated.cpp b/PolyVoxCore/source/SurfaceExtractorsDecimated.cpp
index b275a545..3612d374 100644
--- a/PolyVoxCore/source/SurfaceExtractorsDecimated.cpp
+++ b/PolyVoxCore/source/SurfaceExtractorsDecimated.cpp
@@ -65,7 +65,7 @@ namespace PolyVox
 			generateDecimatedVerticesForSlice(volIter, uLevel, regSlice0, offset, bitmask0, singleMaterialPatch, vertexIndicesX0, vertexIndicesY0, vertexIndicesZ0);
 		}
 
-		for(boost::uint32_t uSlice = 0; ((uSlice <= POLYVOX_REGION_SIDE_LENGTH-1) && (uSlice + offset.getZ() < region.getUpperCorner().getZ())); uSlice += uStepSize)
+		for(boost::uint32_t uSlice = 1; ((uSlice <= POLYVOX_REGION_SIDE_LENGTH) && (uSlice + offset.getZ() <= regVolume.getUpperCorner().getZ())); uSlice += uStepSize)
 		{
 			Region regSlice1(regSlice0);
 			regSlice1.shift(Vector3DInt32(0,0,uStepSize));
diff --git a/PolyVoxCore/source/VolumeChangeTracker.cpp b/PolyVoxCore/source/VolumeChangeTracker.cpp
index 6b933d15..02bd8604 100644
--- a/PolyVoxCore/source/VolumeChangeTracker.cpp
+++ b/PolyVoxCore/source/VolumeChangeTracker.cpp
@@ -64,7 +64,7 @@ namespace PolyVox
 		listToFill.clear();
 
 		//Regenerate meshes.
-		for(uint16_t regionZ = 0; regionZ < POLYVOX_VOLUME_SIDE_LENGTH_IN_REGIONS; ++regionZ)
+		for(uint16_t regionZ = 0; regionZ < POLYVOX_VOLUME_SIDE_LENGTH_IN_REGIONS-1; ++regionZ)
 		//for(uint16_t regionZ = 0; regionZ < 1; ++regionZ)
 		{		
 			for(uint16_t regionY = 0; regionY < POLYVOX_VOLUME_SIDE_LENGTH_IN_REGIONS; ++regionY)