本文選題：虛擬場景 + 視點質(zhì)量��； 參考：《國防科學(xué)技術(shù)大學(xué)》2010年博士論文

【摘要】： 虛擬場景的視點質(zhì)量評價與繪制優(yōu)化是計算機圖形學(xué)和虛擬現(xiàn)實技術(shù)領(lǐng)域中非常重要的研究課題,一方面對場景理解、科學(xué)可視化、三維模型檢索等研究領(lǐng)域具有一定的理論指導(dǎo)意義;另一方面在虛擬戰(zhàn)場、虛擬城市、影視動畫和三維游戲等眾多應(yīng)用領(lǐng)域有著重要的實用價值。如何對虛擬場景的觀察視點進行評價,并從視點觀察質(zhì)量角度出發(fā)對虛擬場景進行繪制優(yōu)化,這一工作具有一定的困難和挑戰(zhàn),同時也是進一步提升虛擬場景觀察和漫游繪制質(zhì)量的必然要求。 本文的研究工作主要涵蓋了虛擬場景的視點質(zhì)量評價、自動漫游路徑生成、網(wǎng)格簡化、地形與地物匹配等方面,對其中的一些理論和應(yīng)用問題進行了深入分析和探討。具體而言,論文的主要工作和貢獻體現(xiàn)在以下幾個方面: 提出了一種特征信息加權(quán)的視點質(zhì)量評價方法。從信息獲取的角度,將虛擬場景的特征信息和幾何信息作為主要評價因素,對虛擬場景的視點質(zhì)量進行評價。首先采用網(wǎng)格顯著度對場景的特征信息進行度量,在此基礎(chǔ)上對觀察視點進行量化處理;然后根據(jù)建立的觀察信道模型,定義了一個理想觀察視點;最后將觀察視點與理想視點之間的相似性測度作為觀察視點的視點質(zhì)量。實驗對比表明本文算法對觀察視點的評價結(jié)果較為客觀,獲得的最優(yōu)觀察視圖具有較好的視覺效果。此外,根據(jù)圖形硬件的高速并行特性,設(shè)計并實現(xiàn)了一種基于CUDA的視點質(zhì)量計算方法,提高了視點質(zhì)量的計算效率。 提出了一種基于視點質(zhì)量評價的自動漫游路徑生成算法。自動漫游路徑的生成包括最優(yōu)視點集選取和路徑生成兩個關(guān)鍵步驟。對于最優(yōu)視點集的選取,提出了兩種不同的方法:一種是采用模糊C-均值聚類算法,根據(jù)聚類中心求解最優(yōu)視點集;另一種是將觀察視點集對應(yīng)的虛視點的視點質(zhì)量作為目標(biāo)函數(shù),并采用蟻群優(yōu)化算法進行求解。在路徑生成的過程中,設(shè)計了一種排序和平滑算法,解決了路徑自交叉和拐點尖銳的問題。算法所生成的自動漫游路徑光滑平整,且沿該路徑觀察時能夠最大限度地獲取場景信息,提高了觀察和漫游繪制的效率與效果。 提出了一種基于視點質(zhì)量評價的網(wǎng)格簡化算法。為了提高場景網(wǎng)格的簡化質(zhì)量,以觀察視點的視點質(zhì)量變化驅(qū)動場景網(wǎng)格的簡化。算法首先在場景網(wǎng)格周圍以最優(yōu)分布或均勻分布方式布置觀察視點;然后采用特征信息加權(quán)的視點質(zhì)量評價方法計算三角形折疊引起的視點質(zhì)量誤差;接著將視點質(zhì)量誤差與二次誤差結(jié)合定義三角形折疊的誤差測度;最后根據(jù)誤差測度確定三角形的折疊次序,從而完成場景網(wǎng)格的簡化。算法能夠保持場景網(wǎng)格中的顯著區(qū)域,并能夠?qū)Σ豢梢娙切芜M行優(yōu)先簡化。 提出了一種基于微分域網(wǎng)格變形算法的地形與地物匹配優(yōu)化算法。為了解決虛擬場景中地形與地物的匹配失真問題,首先提出了一種改進的微分域網(wǎng)格變形算法,根據(jù)頂點的切平面中值坐標(biāo)定義微分坐標(biāo);然后將細節(jié)編碼和解碼過程移植到GPU中,實現(xiàn)了一種圖形硬件加速的微分域網(wǎng)格變形算法;最后根據(jù)地物的底面特征對地形網(wǎng)格進行形變處理。算法不僅實現(xiàn)了虛擬場景中地形與地物的自適應(yīng)匹配,具有較好的匹配效果,而且由于將匹配問題轉(zhuǎn)換為線性系統(tǒng)求解問題,因此具有較高的執(zhí)行效率。 以虛擬戰(zhàn)場環(huán)境的相關(guān)應(yīng)用為任務(wù)背景,設(shè)計并實現(xiàn)了一個優(yōu)化漫游繪制原型系統(tǒng)——BOExplore,對虛擬場景的視點評價與繪制優(yōu)化的研究成果和算法進行了應(yīng)用和驗證,并在相關(guān)項目中得到了應(yīng)用。
[Abstract]:The quality evaluation and rendering optimization of virtual scene is a very important research topic in the field of computer graphics and virtual reality. On the one hand, it has a certain theoretical guiding significance for the research fields such as scene understanding, scientific visualization, 3D model retrieval and so on. On the other hand, virtual battlefield, virtual city, film and television animation and 3D. Many application fields, such as games, have important practical value. How to evaluate the view point of the virtual scene and optimize the virtual scene from the viewpoint of observation quality, this work has some difficulties and challenges, at the same time, it is also the necessary requirement to further improve the quality of virtual scene observation and roaming.
The research work of this paper mainly covers the quality evaluation of the virtual scene, the generation of automatic roaming path, the simplification of the grid, the matching of terrain and ground objects and so on. Some of the theories and application problems of the virtual scene are deeply analyzed and discussed.
A quality evaluation method of feature information weighting is proposed. From the angle of information acquisition, the feature information and geometric information of the virtual scene are used as the main evaluation factors to evaluate the visual point quality of the virtual scene. First, the feature information of the scene is measured by the grid saliency. On this basis, the observation view is carried out. According to the established observation channel model, an ideal observation view is defined. Finally, the similarity measure between the observation point and the ideal point of view is used as the visual point quality of the observation view. The experimental comparison shows that the evaluation result of the observation view is more objective, and the optimal view view has good view. In addition, according to the high speed and parallel characteristics of the graphics hardware, a method of calculating the quality of view based on CUDA is designed and realized, which improves the calculation efficiency of the view point quality.
An automatic roaming path generation algorithm based on view quality evaluation is proposed. The generation of automatic roaming path consists of two key steps: optimal view set selection and path generation. Two different methods are proposed for the selection of optimal view point set: one is to use fuzzy C- mean value clustering algorithm to solve the optimal view according to the cluster center. In the process of path generation, a sort and smoothing algorithm is designed to solve the problem that the path is cross and the turning point is sharp. The automatic roaming path generated by the calculation method is smooth and smooth. When the path is observed, it can maximize scene information and improve the efficiency and effectiveness of observation and roaming rendering.
A mesh simplification algorithm based on view quality evaluation is proposed. In order to improve the simplified quality of the scene grid, the view point quality changes are used to simplify the scene mesh simplification. First, the observation points are arranged in the optimal distribution or uniform distribution around the scene grid, and then the quality of view quality is weighted by the feature information. The evaluation method is used to calculate the quality error of the view point caused by the triangle folding, and then the error measure of the triangle folding is defined by combining the point quality error with the two error. Finally, the order of the triangle is determined according to the error measure, thus the simplification of the scene grid is completed. It can be seen that the triangle is simplified as a priority.
In order to solve the matching distortion of terrain and ground objects in virtual scene, an improved mesh deformation algorithm for differential domain is proposed, which defines the differential coordinates according to the median coordinates of the tangent plane in the vertex, and then encodes and decodes the details. In GPU, a graphic hardware accelerated differential domain mesh deformation algorithm was implemented. Finally, the terrain mesh was deformed according to the ground features of the ground objects. The algorithm not only realized the adaptive matching of terrain and terrain in the virtual scene, but also had better matching effect, and the matching problem was converted to a linear system for solving the matching problem. As a result, it has high efficiency.
With the application of virtual battlefield environment as the task background, an optimized roaming prototype system, BOExplore, is designed and implemented. The research results and algorithms of visual point evaluation and optimization of virtual scene are applied and verified, and they are used in the related projects.

【學(xué)位授予單位】：國防科學(xué)技術(shù)大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2010
【分類號】：TP391.41

【引證文獻】

相關(guān)博士學(xué)位論文 前1條

1 楊超;虛擬戰(zhàn)場中電磁環(huán)境三維建模與繪制方法研究[D];國防科學(xué)技術(shù)大學(xué);2010年

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本文編號：1884580