| In today’s rapidly developing information technology,the advantages of interdisciplinary applications are increasingly prominent,representing a major trend in the future development of science and technology.The rapid development of photogrammetry and computer technology has provided effective means to support the digitization of ancient buildings,as well as opportunities and challenges for the processing of three-dimensional digital real-life models of ancient buildings.Effective digital protection is the fundamental guarantee for the long-term continuation of ancient architecture,and the demand for digital protection is even more urgent due to the long history,culture,and unique architectural characteristics of ancient tower architectural heritage.Tracing the history of pagoda construction in the Ningxia region,the earliest can be traced back to the Eastern Jin Dynasty.There have been approximately 400 pagodas of various sizes and types built by various ethnic groups throughout history.But with the passage of time,many existing ancient pagodas in Ningxia have suffered varying degrees of damage and destruction under the dual influence of natural environment and human factors for hundreds or even thousands of years.It is urgent to carry out effective digital protection for them.This article starts from the perspective of the current lack of efficient and adaptable 3D digital modeling methods for high-rise ancient pagodas.Based on the Motion Recovery Structure Method(SFM)and close-up photography techniques,a highly feasible digital protection scheme is proposed to effectively protect high-rise ancient buildings such as ancient pagodas in Ningxia through 3D digitization,transforming valuable heritage from the real world into digital assets.The main research content and achievements are as follows:(1)In order to explore the application needs and solutions of ancient pagodas in Ningxia region,a systematic review and summary of brick and stone ancient pagodas and 3D modeling related technologies were conducted,mainly including:① the origin and development process,shape classification,construction structure,and the main factors causing their damage;② The actual situation of ancient pagodas in Ningxia region and the existing problems in the modeling methods of ancient pagodas;③ The relevant real-world 3D modeling techniques and methods involved in the paper.(2)Based on the Motion Recovery Structure Method(SFM),a video frame 3D reconstruction method based on SFM is proposed,which solves the problem of unclear image sequence correlation during the 3D reconstruction process.The uncertainty in the number of images collected in the early stage is transformed into the elastic interval extraction of video frame images according to actual modeling requirements in the later modeling process,which greatly improves the modeling success rate.Taking the Feifei Sculpture and Jinbo Pavilion in Huaiyuan Campus of Ningxia University,the Bell and Drum Tower in Xingqing District,and the Pagoda of Chengtian Temple in Yinchuan as the test objects,the feasibility of the video frame sequence modeling method,the applicability considering the complexity of buildings,and the practicality of modeling for towering ancient towers were respectively verified,and the feasibility and superiority of the new method were demonstrated.(3)Taking the drum tower image in Xingqing District as the data sample,we comprehensively compared three software platforms(ContextCapture,RealityCapture,PhotoScan)that implement video frame image reconstruction based on SFM method,and quantitatively analyzed the application effect of each platform from the evaluation indicators such as the ease of operation,the time consumption of 3D reconstruction processing,the spatial precision of the reconstruction model,the integrity of the reconstruction model,and the texture details of the reconstruction model.From the analysis of the comparison results,we can see that,The standardized modeling process of the PS platform has simple operational logic and strong scalability,but the overall effect of the established 3D model is poor and takes a long time;The operational logic of the CC platform is relatively complex,but its comprehensive ability is the most outstanding.The reconstructed real 3D model performs well in terms of accuracy,integrity,and texture details;The performance of the RC platform is relatively balanced,but the overall modeling effect is not as good as the CC platform.(4)On the basis of summarizing the previous experimental modeling work,this paper proposes a UAV three phase loop shot video evenly divided frame modeling method to address the issues of low efficiency and high cost in 3D modeling of towering ancient pagodas.By setting up three phases of high,medium,and low using unmanned aerial vehicles,the towering ancient pagoda is captured and evenly divided into frames for video capture.The Haibao Pagoda in Yinchuan,Ningxia,is selected as an example application object for case modeling,and compared with the widely used unmanned aerial vehicle(UAV)photography inclined photography modeling method,the modeling effect of the two acquisition methods is compared from three aspects of modeling efficiency,modeling air quality and overall model quality.The results show that the modeling effect of the method proposed in this paper is superior to the three-dimensional modeling effect of unmanned aerial vehicle oblique photography.On the basis of optimizing the acquisition process and simplifying equipment conditions,the integrity of the model is ensured,and the modeling efficiency and quality are improved. |
PDF Full Text Request