森林公园虚拟漫游装置关键技术研究
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摘要
森林公园可视化是林业可视化的重要组成部分,也是数字林业不可或缺的一部分。森林公园虚拟漫游装置采用虚拟现实技术,在生动形象展示森林公园景观的同时,使用户能够在虚拟森林公园环境中行走和跑步,实现多感官体验。森林公园虚拟漫游装置作为林业科普装备设计的一个新兴研究内容,可以用来展示森林公园,推广林业文化。
本文在对现有漫游系统分析的基础上,以森林公园景观可视化为研究对象,提出了森林公园虚拟漫游装置的设计方案,解决了漫游装置的技术难点和关键问题,在此基础上,实现了装置开发,实际运行效果良好。本论文的主要工作和创新点包括：
(1)提出了基于跑步机的森林公园虚拟漫游装置的设计方案,主要包括软硬件两大部分。和桌面漫游系统相比,该漫游装置的人机交互不再仅仅局限于鼠标键盘,可以为用户带来更多沉浸感和互动体验。其关键技术主要有以下几个
●设计了基于AT89C51单片机的跑步机硬件控制器,编写了串行通信程序,使跑步机具有串行通信功能,和电脑之间能够实现数据传输。
●开发了基于C++和Virtools的数据通信模块,实现了在电脑上运行的虚拟漫游系统和跑步机之间的实时数据互动。虚拟漫游系统通过串口和数据通信模块,能实时获取跑步机的各项运动参数,用以驱动场景中虚拟人的运动状态和界面信息显示；同时,虚拟场景的路面坡度变化也可以通过数据通信模块和串口控制跑步机跑台的升降,模拟人爬坡的效果。
●引入游戏手柄、wii体感装置等辅助外设,弥补了跑步机单纯直线运动方式、没有转弯功能这一不足,增加了漫游的自主性。
(2)深入研究以树木为主体的虚拟森林公园视景创建,综合使用多种建模技术和优化方法,取得了视觉效果和实时性较好地平衡。
●提出根据森林公园景点分布对虚拟场景进行模型分割和动态载入的方法,提高了系统的渲染速度,便于组织管理场景。
●针对以植被为主体的视景仿真,使用C++开发了一套专用树木载入插件,使SpeedTree中高效的树木效果可以应用到Virtool开发平台。
●使用Virtool的VSL脚本语言近似模拟了水体的折射、反射和菲涅尔等光学现象；模拟森林公园常见的一些自然现象(雨、雪、雾和梅花飘落等)效果,增加了场景的真实性、趣味性和艺术性。
(3)实现了基于局域网的分布式虚拟漫游系统开发,增强了系统的娱乐性、互动性和真实感。
(4)将系统关键技术应用于森林公园数字旅游、林业科普教育和林业文化推广,提出并初步论述了数字林业科普产品设计理论,分析了其研究内容、构成结构、研究价值和设计特征。数字林业科普产品对于展示林业知识推广林业文化具有重要意义。
The visualization of forest park is an important component of forestry visualization, and it is an indispensable part of digital forestry. The virtual walkthrough device of forest park based on virtual reality technology can vividly display its landscape. At the same time, users can walk or run in virtual environment of forest park, and achieve multi-sensory experiences. The virtual walkthrough device of forest park is a new studying field of the forestry equipment engineering, which can be used to exhibit forest parks and popularize the forestry culture.
This paper focuses on the visualization of forest park landscape. On the base of analyzing the present walkthrough systems, it proposes a new design scheme of virtual walkthrough device of forest park, and solves the key technologies and difficult problems. On these bases, this paper develops the device and the running result is good. The main contents and innovations of this paper can be listed as follows:
(1) This paper presents a kind of design scheme of virtual walkthrough device of forest park based on treadmills, which includes two parts:software and hardware. Compared with desktop walkthrough systems, the man and computer interaction of this walkthrough system is not only restricted to the control of mouse and keyboard, but it also brings more immersion and interactive experiences for users. The key technologies are as follows.
This paper designs the hardware controller of household treadmill based on AT89C51 microcontroller, and compiles serial communication procedure. Those designs realize the twoway transmission of datas between computers and treadmills.
The paper develops data communication modules based on C++ and Virtools, which realize the real-time sending and receiving of data between treadmills and virtual scenes. That is to say, virtual walkthrough system running on computers will collect real-time motion dates from users on treadmills, and those datas will be used to drive the motion of virtual human in the virtual scenes and display interface information; at the same time, the road slope in virtual environment can control the ascending and descending of treadmills.
The paper also adopts peripherals, such as gamepad and wii remote, to increase the walkthrough autonomy, that remedies the deficiency of the rectilinear motion and without turn function of treadmills.
(2) This paper makes a thorough study in the scene simulation of forest parks composed mainly of trees. The paper utilizes comprehensively various modeling technologies and methods, and achieves a good balance between visual effect and real-time performance.
This paper proposes a method for segmenting and dynamically loading virtual scenes based on scenic spots distribution of forest park. This method enhances the rendering speed and facilitates the organization and management of virtual scenes.
Aiming at the visual simulation with vegetation remaining dominant, the paper develops a plug-in of vegetation simulation, which makes the efficient tree effect in SpeedTree can be applied into Virtools.
This paper approximately simulates the optical phenomena, such as the reflections, refraction and Fresnel effect of water, by using scripting language VSL of Virtools. And it also simulates some common natural phenomena (rain, snow, fog, etc) in forest park. Those simulations add the realness, enjoyment and artistry to the scene.
(3) This paper implements a distributed walkthrough system via a LAN that enhances the entertainment, interactivity and realism of the system.
(4) The result of this paper is applied to digital tourism of forest parks, forestry science popularization and forestry culture promotion. This paper provides and preliminarily discusses the digital product design theory of forestry science popularization, analyzing the research significance and content, the structure and design characters. The digital products of forestry science popularization has significant meaning to the popularization of forestry knowledge and promotion of forestry culture.
本文在对现有漫游系统分析的基础上,以森林公园景观可视化为研究对象,提出了森林公园虚拟漫游装置的设计方案,解决了漫游装置的技术难点和关键问题,在此基础上,实现了装置开发,实际运行效果良好。本论文的主要工作和创新点包括：
(1)提出了基于跑步机的森林公园虚拟漫游装置的设计方案,主要包括软硬件两大部分。和桌面漫游系统相比,该漫游装置的人机交互不再仅仅局限于鼠标键盘,可以为用户带来更多沉浸感和互动体验。其关键技术主要有以下几个
●设计了基于AT89C51单片机的跑步机硬件控制器,编写了串行通信程序,使跑步机具有串行通信功能,和电脑之间能够实现数据传输。
●开发了基于C++和Virtools的数据通信模块,实现了在电脑上运行的虚拟漫游系统和跑步机之间的实时数据互动。虚拟漫游系统通过串口和数据通信模块,能实时获取跑步机的各项运动参数,用以驱动场景中虚拟人的运动状态和界面信息显示；同时,虚拟场景的路面坡度变化也可以通过数据通信模块和串口控制跑步机跑台的升降,模拟人爬坡的效果。
●引入游戏手柄、wii体感装置等辅助外设,弥补了跑步机单纯直线运动方式、没有转弯功能这一不足,增加了漫游的自主性。
(2)深入研究以树木为主体的虚拟森林公园视景创建,综合使用多种建模技术和优化方法,取得了视觉效果和实时性较好地平衡。
●提出根据森林公园景点分布对虚拟场景进行模型分割和动态载入的方法,提高了系统的渲染速度,便于组织管理场景。
●针对以植被为主体的视景仿真,使用C++开发了一套专用树木载入插件,使SpeedTree中高效的树木效果可以应用到Virtool开发平台。
●使用Virtool的VSL脚本语言近似模拟了水体的折射、反射和菲涅尔等光学现象；模拟森林公园常见的一些自然现象(雨、雪、雾和梅花飘落等)效果,增加了场景的真实性、趣味性和艺术性。
(3)实现了基于局域网的分布式虚拟漫游系统开发,增强了系统的娱乐性、互动性和真实感。
(4)将系统关键技术应用于森林公园数字旅游、林业科普教育和林业文化推广,提出并初步论述了数字林业科普产品设计理论,分析了其研究内容、构成结构、研究价值和设计特征。数字林业科普产品对于展示林业知识推广林业文化具有重要意义。
The visualization of forest park is an important component of forestry visualization, and it is an indispensable part of digital forestry. The virtual walkthrough device of forest park based on virtual reality technology can vividly display its landscape. At the same time, users can walk or run in virtual environment of forest park, and achieve multi-sensory experiences. The virtual walkthrough device of forest park is a new studying field of the forestry equipment engineering, which can be used to exhibit forest parks and popularize the forestry culture.
This paper focuses on the visualization of forest park landscape. On the base of analyzing the present walkthrough systems, it proposes a new design scheme of virtual walkthrough device of forest park, and solves the key technologies and difficult problems. On these bases, this paper develops the device and the running result is good. The main contents and innovations of this paper can be listed as follows:
(1) This paper presents a kind of design scheme of virtual walkthrough device of forest park based on treadmills, which includes two parts:software and hardware. Compared with desktop walkthrough systems, the man and computer interaction of this walkthrough system is not only restricted to the control of mouse and keyboard, but it also brings more immersion and interactive experiences for users. The key technologies are as follows.
This paper designs the hardware controller of household treadmill based on AT89C51 microcontroller, and compiles serial communication procedure. Those designs realize the twoway transmission of datas between computers and treadmills.
The paper develops data communication modules based on C++ and Virtools, which realize the real-time sending and receiving of data between treadmills and virtual scenes. That is to say, virtual walkthrough system running on computers will collect real-time motion dates from users on treadmills, and those datas will be used to drive the motion of virtual human in the virtual scenes and display interface information; at the same time, the road slope in virtual environment can control the ascending and descending of treadmills.
The paper also adopts peripherals, such as gamepad and wii remote, to increase the walkthrough autonomy, that remedies the deficiency of the rectilinear motion and without turn function of treadmills.
(2) This paper makes a thorough study in the scene simulation of forest parks composed mainly of trees. The paper utilizes comprehensively various modeling technologies and methods, and achieves a good balance between visual effect and real-time performance.
This paper proposes a method for segmenting and dynamically loading virtual scenes based on scenic spots distribution of forest park. This method enhances the rendering speed and facilitates the organization and management of virtual scenes.
Aiming at the visual simulation with vegetation remaining dominant, the paper develops a plug-in of vegetation simulation, which makes the efficient tree effect in SpeedTree can be applied into Virtools.
This paper approximately simulates the optical phenomena, such as the reflections, refraction and Fresnel effect of water, by using scripting language VSL of Virtools. And it also simulates some common natural phenomena (rain, snow, fog, etc) in forest park. Those simulations add the realness, enjoyment and artistry to the scene.
(3) This paper implements a distributed walkthrough system via a LAN that enhances the entertainment, interactivity and realism of the system.
(4) The result of this paper is applied to digital tourism of forest parks, forestry science popularization and forestry culture promotion. This paper provides and preliminarily discusses the digital product design theory of forestry science popularization, analyzing the research significance and content, the structure and design characters. The digital products of forestry science popularization has significant meaning to the popularization of forestry knowledge and promotion of forestry culture.
引文
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