Combining The "Fractal Viewing Distance" Texture Compression And Color Polygon Texture Organization For Visualization Of 3D Models

Texture data is an important part of building a true 3D model of the city,which usually takes up a lot of memory,making it difficult to realize smooth and stable dynamic visualization of the 3D model.Therefore,the effective organization and scheduling of texture data have become one of the most important and hot research contents in the world.In view of the current research status of texture data and organization in 3D model visualization at home and abroad,this paper proposes a method of combining the "fractal viewing distance" texture compression and color polygon texture organization for visualization of 3D models.The proposed method can express the visual characteristics of buildings with fewer texture data,greatly improve the rendering efficiency and visualization speed of large-scale 3D models,and has great research value.Combining the "fractal viewing distance" texture compression and color polygon texture organization for visualization of 3D models proposed in this paper focuses on the following aspects.Firstly,aiming at the current situation of texture compression and data management at home and abroad,the theoretical and mathematical foundation of FVD model is introduced,focuses on the analysis of the existing basic fractal coding algorithms and their advantages and disadvantages,expounds the necessity of texture compression according to the position and distance of the viewpoint in 3D model visualization.Secondly,a fractal viewing distance texture compression and color polygon texture organization is proposed based on the view distance and visibility of the target fa(?)ade.When the visual distance meets the texture calling condition and the target facade is visible,the texture data is decompressed dynamically and the number of texture resampling is determined to create multi-resolution texture data.When the visual distance does not meet the texture call condition but the target facade is visible,the texture segmentation algorithm is used to create a color texture tree,and the color polygons are generated by merging nodes to represent the building facade texture.Based on the structure of 3D model data,the merits and demerits of spatial data storage structure are compared and summarized,this paper uses relational databases to achieve efficient storage and rapid recall of building texture data.Then,this paper introduces the texture mapping algorithm of the 3D model.The FVD texture dynamic scheduling scheme is proposed based on the AABB bounding box.This method loads scene data according to the initial view point position and line of sight direction.When the view point is constantly changing,the condition is judged and the corresponding texture data is called.If the 3D building model is outside the frustum,the model data does not need to be rendered.If the target building’s facade is not visible,the building’s facade needs to be removed.The corresponding resolution texture or color polygon texture is called according to the viewing angle and distance to complete the dynamic visualization of the 3D building model.Finally,experiments are conducted for the method proposed in this paper,based on building texture data from two study areas.The results of the experiments are compared in terms of memory usage and frame rate using 3ds Max,Sketch Up and the method proposed in this paper.The experimental results show that,compared with 3ds Max and Sketch Up Pro,this method reduces memory usage by 36.5% and 30.9% respectively,and increases frame rate by7% and 10.9% respectively in study area 1;this method reduces memory usage by 36.5% and30.9% respectively in study area 2,and increases frame rate by 7% and 10.9% respectively.