Research And Application On Key Technology Of3D Urban Planning Aided System

With the development of computer hardware and software technologies, office automation becomes an inevitable trend in every walk of life. Due to the speciality of urban planning as an industry, apart from informatization and automation of the office, the analyses and effects of scheme in all links such as the designing and auditing process set a higher visual requirement. This paper attempts to make an in-depth study on the correlation theories and algorithms for aided analyses based on urban planning in which three dimensions are measurable.At the very beginning, some ideas relating to the3D digital city and its development at home and abroad are briefly introduced. The advantages and necessity of the adoption of3D visualization in the planning are discussed in the urban planning, so as to point out the direction and objective of this study.In the main body of this paper, two aspects are studied. One is about the real-time rendering technology used in large-scale3D terrains, and the other is about aided-analysis theories and algorithms in urban planning. In order to meet real-time rendering of large-scale terrain requirements, a way combining quad tree structure and LOD for terrain simplification was adopted in this research. While3D scene roaming, a mechanism of multi-level buffering was used for data scheduling and rendering under the condition of quickly viewpoint transformation. At the same time, an adaptive LOD scheduling which comprehensive consideration of frame rate and subdivision evaluation function was proposed. A multi-level texture mapping method consistent with the terrain scheduling was used to render the image texture. And the large-scale3D terrain visualization was realized based on the simplify methods.From the perspective of aided analyses in planning, this paper highlights the visibility analysis and sunshine analysis, through analyses on the indivisibility between surface features, the simulations of natural light shadows of buildings and audio-visual presentations for planning schemes for functions such as single-point natural light.In the last part, this paper summarizes the whole process of this study and points out the limitations in this systematic study, so as to give suggestions to its further explorations.