diff --git a/include/SurfaceEdge.h b/include/SurfaceEdge.h
index 3fbec2cd..d3f3534e 100644
--- a/include/SurfaceEdge.h
+++ b/include/SurfaceEdge.h
@@ -38,28 +38,28 @@ namespace Ogre
 
 		bool isDegenerate(void);
 
-		const SurfaceVertexIterator& getTarget(void);
-		const SurfaceVertexIterator& getSource(void);
-		const SurfaceEdgeIterator& getOtherHalfEdge(void);
-		const SurfaceEdgeIterator& getPreviousHalfEdge(void);
-		const SurfaceEdgeIterator& getNextHalfEdge(void);
-		const SurfaceTriangleIterator& getTriangle(void);
+		const SurfaceVertexIterator& getTarget(void) const;
+		const SurfaceVertexIterator& getSource(void) const;
+		const SurfaceEdgeIterator& getOtherHalfEdge(void) const;
+		const SurfaceEdgeIterator& getPreviousHalfEdge(void) const;
+		const SurfaceEdgeIterator& getNextHalfEdge(void) const;
+		const SurfaceTriangleIterator& getTriangle(void) const;
 
-		void setPreviousHalfEdge(const SurfaceEdgeIterator& previousHalfEdgeToSet);
-		void setNextHalfEdge(const SurfaceEdgeIterator& nextHalfEdgeToSet);
-		void setTriangle(const SurfaceTriangleIterator& triangleToSet);
+		void setPreviousHalfEdge(const SurfaceEdgeIterator& previousHalfEdgeToSet) const;
+		void setNextHalfEdge(const SurfaceEdgeIterator& nextHalfEdgeToSet) const;
+		void setTriangle(const SurfaceTriangleIterator& triangleToSet) const;
 
-		void pairWithOtherHalfEdge(const SurfaceEdgeIterator& otherHalfEdgeToPair);
+		void pairWithOtherHalfEdge(const SurfaceEdgeIterator& otherHalfEdgeToPair) const;
 
 	private:
 		SurfaceVertexIterator target;
 		SurfaceVertexIterator source;
 
-		SurfaceEdgeIterator previousHalfEdge;
-		SurfaceEdgeIterator nextHalfEdge;
-		SurfaceEdgeIterator otherHalfEdge;
+		mutable SurfaceEdgeIterator previousHalfEdge;
+		mutable SurfaceEdgeIterator nextHalfEdge;
+		mutable SurfaceEdgeIterator otherHalfEdge;
 
-		SurfaceTriangleIterator triangle;
+		mutable SurfaceTriangleIterator triangle;
 	};	
 }
 
diff --git a/include/SurfaceTypes.h b/include/SurfaceTypes.h
index c33b6f96..f3337606 100644
--- a/include/SurfaceTypes.h
+++ b/include/SurfaceTypes.h
@@ -14,4 +14,4 @@ namespace Ogre
 	typedef std::set<SurfaceEdge>::const_iterator SurfaceEdgeConstIterator;
 }
 
-#endif
\ No newline at end of file
+#endif
diff --git a/include/SurfaceVertex.h b/include/SurfaceVertex.h
index 29335766..17d561db 100644
--- a/include/SurfaceVertex.h
+++ b/include/SurfaceVertex.h
@@ -44,17 +44,17 @@ namespace Ogre
 		const UIntVector3& getPosition(void) const;	
 
 		void setAlpha(float alphaToSet);	
-		void setEdge(const SurfaceEdgeIterator& edgeToSet);
-		void setNormal(const Vector3& normalToSet);			
+		void setEdge(const SurfaceEdgeIterator& edgeToSet) const;
+		void setNormal(const Vector3& normalToSet) const;
 
-		std::string toString(void);
+		std::string toString(void) const;
 
 	private:
 		UIntVector3 position;
-		Vector3 normal;
+		mutable Vector3 normal;
 		float alpha;
 
-		SurfaceEdgeIterator edge;		
+		mutable SurfaceEdgeIterator edge;		
 
 		unsigned long m_uHash;
 	};
diff --git a/source/SurfaceEdge.cpp b/source/SurfaceEdge.cpp
index 1ba57854..0e3848ff 100644
--- a/source/SurfaceEdge.cpp
+++ b/source/SurfaceEdge.cpp
@@ -50,54 +50,54 @@ namespace Ogre
 		return false;
 	}
 
-	const SurfaceVertexIterator& SurfaceEdge::getTarget(void)
+	const SurfaceVertexIterator& SurfaceEdge::getTarget(void) const
 	{
 		return target;
 	}
 
-	const SurfaceVertexIterator& SurfaceEdge::getSource(void)
+	const SurfaceVertexIterator& SurfaceEdge::getSource(void) const
 	{
 		return source;
 	}
 
-	void SurfaceEdge::pairWithOtherHalfEdge(const SurfaceEdgeIterator& otherHalfEdgeToPair)
+	void SurfaceEdge::pairWithOtherHalfEdge(const SurfaceEdgeIterator& otherHalfEdgeToPair) const
 	{
 		otherHalfEdge = otherHalfEdgeToPair;
 		previousHalfEdge = otherHalfEdgeToPair;
 		nextHalfEdge = otherHalfEdgeToPair;
 	}
 
-	const SurfaceEdgeIterator& SurfaceEdge::getOtherHalfEdge(void)
+	const SurfaceEdgeIterator& SurfaceEdge::getOtherHalfEdge(void) const
 	{
 		return otherHalfEdge;
 	}
 
-	const SurfaceEdgeIterator& SurfaceEdge::getPreviousHalfEdge(void)
+	const SurfaceEdgeIterator& SurfaceEdge::getPreviousHalfEdge(void) const
 	{
 		return previousHalfEdge;
 	}
 
-	const SurfaceEdgeIterator& SurfaceEdge::getNextHalfEdge(void)
+	const SurfaceEdgeIterator& SurfaceEdge::getNextHalfEdge(void) const
 	{
 		return nextHalfEdge;
 	}
 
-	const SurfaceTriangleIterator& SurfaceEdge::getTriangle(void)
+	const SurfaceTriangleIterator& SurfaceEdge::getTriangle(void) const
 	{
 		return triangle;
 	}
 
-	void SurfaceEdge::setPreviousHalfEdge(const SurfaceEdgeIterator& previousHalfEdgeToSet)
+	void SurfaceEdge::setPreviousHalfEdge(const SurfaceEdgeIterator& previousHalfEdgeToSet) const
 	{
 		previousHalfEdge = previousHalfEdgeToSet;
 	}
 
-	void SurfaceEdge::setNextHalfEdge(const SurfaceEdgeIterator& nextHalfEdgeToSet)
+	void SurfaceEdge::setNextHalfEdge(const SurfaceEdgeIterator& nextHalfEdgeToSet) const
 	{
 		nextHalfEdge = nextHalfEdgeToSet;
 	}
 
-	void SurfaceEdge::setTriangle(const SurfaceTriangleIterator& triangleToSet)
+	void SurfaceEdge::setTriangle(const SurfaceTriangleIterator& triangleToSet) const
 	{
 		triangle = triangleToSet;
 	}
diff --git a/source/SurfaceVertex.cpp b/source/SurfaceVertex.cpp
index 9c4df628..bf1dd09b 100644
--- a/source/SurfaceVertex.cpp
+++ b/source/SurfaceVertex.cpp
@@ -49,18 +49,18 @@ namespace Ogre
 		alpha = alphaToSet;
 	}
 
-	void SurfaceVertex::setEdge(const SurfaceEdgeIterator& edgeToSet)
+	void SurfaceVertex::setEdge(const SurfaceEdgeIterator& edgeToSet) const
 	{
 		edge = edgeToSet;
 	}
 
-	void SurfaceVertex::setNormal(const Vector3& normalToSet)
+	void SurfaceVertex::setNormal(const Vector3& normalToSet) const
 	{
 		normal = normalToSet;
 		normal.normalise();
 	}		
 
-	std::string SurfaceVertex::toString(void)
+	std::string SurfaceVertex::toString(void) const
 	{
 		std::stringstream ss;
 		ss << "SurfaceVertex: Position = (" << position.x << "," << position.y << "," << position.z << "), Normal = " << StringConverter::toString(normal);