Tree Axis Structure Simplification Correspondent to Botanical Properties

In order to describe the tree topology more efficiently for modeling and biological calculation, a ternary tree data structure is introduced in this paper. The data structure of a ternary tree and the topological structure of a real tree constitute a mapping, which presents the biological properties of plant axes and the relationships among plant axes of different tiers. The simplification of tree axes has explicit botanical significance. Biological properties are considered, and the fidelity is kept as high as possible between the simplified tree axes and biological features such as canopy envelope's shape, volume and the biomass distribution inside. This paper applies the ternary tree data structure and the tree axis simplification method to simplify tree modeling and therefore generates Levels of Detail (LOD) models. Fast display of the LOD models is achieved with graphics hardware acceleration. Experimental results indicate that the introduced structural simplification is highly correspondent to a real tree's botanical properties, keeps visual equivalence in a satisfactory degree, and is smooth in the transition between levels of detail of models. Furthermore, the approach is advantageous for graphics hardware acceleration.