针对传统古建筑数字化技术的不足和接触测量对建筑物造成"二次伤害",以西北民族大学蝴蝶厅异地重建项目为例,提出了一种结合三维激光扫描技术和现代测量技术以及本体思维进行室内外一体化三维建模的研究思路。首先给出了基于三维激光扫描技术的建模流程;其次,对点云数据处理和三维实体重建两个核心步骤,重点对点云数据的配准拼接、去噪简化和提取轮廓线、三维几何建模和纹理贴图等步骤进行详细论述。本体思维用于基于三维激光扫描的古建筑三维建模,可以有效指导古建筑构件分类建模,提高建模效率。结果表明:三维激光扫描技术适用于具有高复杂度几何特征的蝴蝶厅精细化、真实感建模,为西北民族大学蝴蝶厅古建筑文化遗产未来的开发、保护、维修、恢复重建与虚拟地理环境等提供高精度的数据基准。
It is difficult to obtain complete and accurate geometric information by traditional survey and measurement methods.And it may induce secondary harm to the cultural heritage with frequent contact in the measurement process.3Dlaser scanning and other technologies were used to create realistic,fine 3D models of Butterfly hall in Northwest University for Nationalities.Firstly,3D modeling process based on 3Dlaser scanning technology was given;Secondly,the accuracy of 3Dlaser scanner was analyzed in the theoretical and practical perspectives,and in the point cloud data processing using feature points and control points measured by total station to check,position error were within 5 mm.Thirdly,some core steps in point cloud data processing and three-dimensional reconstruction,in particular point cloud data registration,simplification and de-noising,components contour extraction,three-dimensional geometric modeling and texture mapping were discussed in detail.In addition,the 3D modeling idea based on ontology was proposed,and the ontology model of the ancient building in the Protege3.4.4platform was presented.Application results show that the 3Dlaser scanning technology is well suited for precise,realistic modeling of Butterfly hall in Northwest University for Nationalities with highly complex geometric characteristics,as provides high accuracy data base for future development and protection,maintenance,restoration reconstruction and virtual geographic environment etc.