Research On The Technology Of3D Plants Model Simplification And Reconstruction On Mobile Terminals

In recent years, smart phones and tablet computer as the typical representative of mobile devices are spreading rapidly, with their using number beyond the traditional personal computer, and are expected in the near future to obtain more extensive application space than the traditional personal computer.3D applications scenes for resource-constrained mobile device are also increasing, such as3D games, virtual exhibition, film special effects, location-based services, animation and advertising etc. Trees are not only ubiquitous in the real life environment, but also is a indispensable plant type of nature. Besides, it is an important influential factor of immersive and fidelity of virtual environment. Because the trees in nature are various shapes, variety, with their topology structures complicated, if you want to build a three-dimensional trees model with realistic visual effects, the modeling process is very tedious and time-consuming. Meanwhile, because the current network bandwidth, latency, congestion and other network elements as well as the limitation of mobile terminal hardware conditions factors, have seriously affected the synchronization of real-time application for plant models in the mobile terminal. In response to the above questions, this paper focuses on the three-dimensional trees model of plant model for the study, and carried out research on the technology of3d plants model simplification and reconstruction on mobile terminals. This paper based on the topological structure characteristics of3d tree model proposes to simplify branches and canopy parts of the model respectively, and on the basis of the lightweight model carries out model building method based on skeleton personalized editor. The main work and results of this paper are as follows:(1) Based on model geometry complex feature of point and surface, in this paper adopts an overall model simplification strategy of preserve the visual importance. First of all, we separate the whole tree model into branches parts and canopy parts, and simplify the two parts respectively. Then, in order to preserve the visual perception characteristics of tree models, this paper combines model visual important area with different levels of simplification strategies. This will not only simplify the tree models effectively, accelerate network transmission efficiency and rendering speed of the model, but also maintain the original tree model visual perception effect.(2)Tree branches are an important part of three-dimensional model, and it is also the key factor affecting the overall topology of tree models. Therefore, this paper adopts a simplification method combined with shape decomposition and distance transform of3d tree branches model. Then, use model reconstruction methods based on the round table, trapezoidal plane and interpolation to reconstruct branches of tree models. This method not only can be effectively extract the skeleton structure of the original tree model, and the model reconstruction method can better restore the geometry of the original tree. Therefore, this method can effectively simplify the original tree branches patch information, and be able to quickly reconstruct the tree branches model.(3)In order to further simplify the number of three-dimensional mesh of trees model, reduce the model network transmission time and rendering time, this paper proposes a3d tree canopy model simplification and reconstruction technology that based on convex hull texture template mapping, through the convex hull of the crown to represent the overall topology of the crown, and then to fill it with standard branches templates from the existing texture template library.3d tree model crown has been reconstructed according to the geometric space formed by the convex hull, which is aimed at achieving the simplification of geometry information of crown.(4) In order to be able to quickly and diversely construct3d tree model for mobile terminals, this paper proposes a model building method based on personalized editing skeleton of tree models. The essence is that on the basis of the lightweight trees model frame structure, new bone structure of the trees model is formed through interactive personalized skeleton details of tree models. Using trees model reconstruction technology, finally realizes the rapid modeling of3d tree model. Experiments show that the method can quickly constructs trees lightweight models of different forms of the same species.(5) In order to validate the effectiveness of the model simplification and personalized editing method, this paper designs and implements three-dimensional tree model simplification and personalized editing system. Tree model simplification and personalized editing function is provided by the PC client of system’s interaction layer, and storage original tree model to the server after model been simplified and interactive personalized editing. Mobile terminal can according to need to download the file tree model, and rendering and roaming in the terminal.