[octree] Add reference to neighbor method

include/inexor/vulkan-renderer/world/cube.hpp

@@ -170,9 +170,12 @@ class Cube : public std::enable_shared_from_this<Cube> {
     /// @param update_invalid If true it will update invalid polygon caches.
     [[nodiscard]] std::vector<PolygonCache> polygons(bool update_invalid = false) const;
 
-    /// Get the neighbor of this cube.
+    /// Get the (face) neighbor of this cube by using a similar implementation to Samets "OT_GTEQ_FACE_NEIGHBOR(P,I)".
+    /// @brief Get the (face) neighbor of this cube.
     /// @param axis The axis on which to get the neighboring cube
     /// @param direction Whether to get the cube which is above or below this cube on the selected axis
+    /// @see Samet, H. (1989) Neighbor finding in Images Represented by Octrees. Computer Vision, Graphics, and
+    /// Image Processing. 46 (3), 367-386. Available from: http://www.cs.umd.edu/~hjs/pubs/SameCVGIP89.pdf
     [[nodiscard]] std::shared_ptr<Cube> neighbor(NeighborAxis axis, NeighborDirection direction);
 };