diff --git a/library/PolyVoxCore/include/PolyVoxCore/DefaultMarchingCubesController.h b/library/PolyVoxCore/include/PolyVoxCore/DefaultMarchingCubesController.h
index 892b8004..55eef19e 100644
--- a/library/PolyVoxCore/include/PolyVoxCore/DefaultMarchingCubesController.h
+++ b/library/PolyVoxCore/include/PolyVoxCore/DefaultMarchingCubesController.h
@@ -103,6 +103,14 @@ namespace PolyVox
 			return 1;
 		}
 
+		/**
+		 * Returns a material which is in some sense a weighted combination of the supplied materials.
+		 *
+		 * The Marching Cubes algotithm generates vertices which lie between voxels, and ideally the material of the vertex should be interpolated from the materials
+		 * of the voxels. In practice, that material type is often an integer identifier (e.g. 1 = rock, 2 = soil, 3 = grass) and an interpolation doean't make sense
+		 * (e.g. soil is not a combination or rock and grass). Therefore this default interpolation just return one material or the other, but if more advanced voxel
+		 * types do support interpolation then it can be implemented in this function.
+		 */
 		MaterialType blendMaterials(MaterialType a, MaterialType b, float weight)
 		{
 			if(weight < 0.5f)