In keeping with this category, highlighting the dynamic balance between the Rational and Natural worlds, Geometric Form/Organic Matrix captures one specific method of achieving this balance. In this theme, a purely geometric form, often based on a primitive such as a cube or rectangle, defines an absolute outer boundary volume. Then a cellular matrix of internal structures fills in the interior void. The effect suggests that a natural cellular volume has been sliced and defined by an imposed outer geometry. Most famously used recently in the Water Cube stadium in Beijing, this theme has also been present throughout time: a lathed wooden bowl showing the interior wood grain structure expresses the same balance of rational and natural: an outer form controlled by the human mind, exposing the inherent structure of the natural material. To date, this technique has been primarily used in Architecture and Furniture, with some inroads into the Product category. Also, this trend is highly related to Organic Forms/Geometric Matrix, which inverts the relationship between form and interior structure.