Aiming to deal with the difficult issues of terrain data model simplification and crack disposal,the paper proposed an improved level of detail(LOD)terrain rendering algorithm,in which a variation coefficient of eleva...Aiming to deal with the difficult issues of terrain data model simplification and crack disposal,the paper proposed an improved level of detail(LOD)terrain rendering algorithm,in which a variation coefficient of elevation is introduced to express the undulation of topography.Then the coefficient is used to construct a node evaluation function in the terrain data model simplification step.Furthermore,an edge reduction strategy is combined with the improved restrictive quadtree segmentation to handle the crack problem.The experiment results demonstrated that the proposed method can reduce the amount of rendering triangles and enhance the rendering speed on the premise of ensuring the rendering effect compared with a traditional LOD algorithm.展开更多
起重机作为广泛应用的特种装备,运行危险性大,极易发生安全事故。为降低由操作不当引起的安全事故,国家高度重视起重机的安全培训工作。目前培训操作多为传统的示教式培训,培训成本高、效果差。虚拟现实技术具有沉浸式、交互性、多感知...起重机作为广泛应用的特种装备,运行危险性大,极易发生安全事故。为降低由操作不当引起的安全事故,国家高度重视起重机的安全培训工作。目前培训操作多为传统的示教式培训,培训成本高、效果差。虚拟现实技术具有沉浸式、交互性、多感知等优点。基于此,采用虚拟现实技术建立起重装备培训和考核系统,大幅提升工人培训效果。为还原起重机真实使用场景,采用逆向工程技术对起重机及起重机厂房进行建模;针对三维虚拟场景真实性以及模型数量巨大交互模型复用性差的问题,采用细节层次(levels of detail,LOD)模型构建起重装备几何模型,从而优化系统的真实感和实时性;利用Unity平台实现了起重装备的三维场景漫游、碰撞检测和快速导航;基于MySQL数据库,实时存储培训数据以及起重机重要参数数据;依据现有桥机平台对虚拟平台进行了验证,结果显示该起重机虚拟现实培训系统可以在降低培训成本的同时大幅提升了培训感官,实验效果良好。展开更多
基金Supported by the National Natural Science Foundation of China(61363075)the National High Technology Research and Development Program of China(863 Program)(2012AA12A308)the Yue Qi Young Scholars Program of China University of Mining&Technology,Beijing(800015Z1117)
文摘Aiming to deal with the difficult issues of terrain data model simplification and crack disposal,the paper proposed an improved level of detail(LOD)terrain rendering algorithm,in which a variation coefficient of elevation is introduced to express the undulation of topography.Then the coefficient is used to construct a node evaluation function in the terrain data model simplification step.Furthermore,an edge reduction strategy is combined with the improved restrictive quadtree segmentation to handle the crack problem.The experiment results demonstrated that the proposed method can reduce the amount of rendering triangles and enhance the rendering speed on the premise of ensuring the rendering effect compared with a traditional LOD algorithm.
文摘起重机作为广泛应用的特种装备,运行危险性大,极易发生安全事故。为降低由操作不当引起的安全事故,国家高度重视起重机的安全培训工作。目前培训操作多为传统的示教式培训,培训成本高、效果差。虚拟现实技术具有沉浸式、交互性、多感知等优点。基于此,采用虚拟现实技术建立起重装备培训和考核系统,大幅提升工人培训效果。为还原起重机真实使用场景,采用逆向工程技术对起重机及起重机厂房进行建模;针对三维虚拟场景真实性以及模型数量巨大交互模型复用性差的问题,采用细节层次(levels of detail,LOD)模型构建起重装备几何模型,从而优化系统的真实感和实时性;利用Unity平台实现了起重装备的三维场景漫游、碰撞检测和快速导航;基于MySQL数据库,实时存储培训数据以及起重机重要参数数据;依据现有桥机平台对虚拟平台进行了验证,结果显示该起重机虚拟现实培训系统可以在降低培训成本的同时大幅提升了培训感官,实验效果良好。
