本文選題：水面渲染　切入點(diǎn)：投影網(wǎng)格　出處：《電子科技大學(xué)》2009年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】： 隨著計(jì)算機(jī)軟硬件技術(shù)的不斷發(fā)展,三維圖形引擎技術(shù)逐漸成為計(jì)算機(jī)圖形學(xué)的主要研究?jī)?nèi)容之一。它在虛擬現(xiàn)實(shí)、數(shù)字城市、影視廣告、計(jì)算機(jī)輔助設(shè)計(jì)和科學(xué)計(jì)算可視化等各個(gè)方面都發(fā)揮著巨大的作用。用計(jì)算機(jī)模擬自然界的各種自然現(xiàn)象是三維圖形引擎中的關(guān)鍵技術(shù)。自然景物有著形態(tài)復(fù)雜,隨機(jī)變化等特點(diǎn),難以用確定的數(shù)學(xué)模型來(lái)表達(dá)和研究。與模擬火焰、云、山脈和雨水等自然現(xiàn)象相比,海面以其復(fù)雜的運(yùn)動(dòng)規(guī)則和光學(xué)特性使得對(duì)海面的模擬更加具有挑戰(zhàn)性。 對(duì)此,本文從國(guó)內(nèi)外的研究現(xiàn)狀出發(fā),對(duì)海面的幾何建模和光學(xué)建模進(jìn)行深入研究,并在海面網(wǎng)格生成技術(shù)和大規(guī)模海面的場(chǎng)景管理上進(jìn)行改進(jìn)。從而給出大規(guī)模海面實(shí)時(shí)渲染的步驟和大規(guī)模海面場(chǎng)景管理的優(yōu)化算法。 在海面的幾何建模方面,以現(xiàn)有的投影網(wǎng)格LOD算法為出發(fā)點(diǎn),構(gòu)造出限制采樣精度的投影網(wǎng)格,此方法改進(jìn)了舊的投影網(wǎng)格算法在視點(diǎn)離水面較近時(shí)采樣頻率陡增,采樣點(diǎn)過(guò)密而導(dǎo)致水面網(wǎng)格不平滑的現(xiàn)象,能很好地與快速傅立葉變換(FFT)算法生成的水面相結(jié)合。同時(shí)該算法也在一定程度下減少了投影網(wǎng)格的三角形面片數(shù),提高了渲染效率。 在海面高度場(chǎng)的生成方面,本文對(duì)各種文獻(xiàn)資料進(jìn)行深入分析研究之后,運(yùn)用海洋統(tǒng)計(jì)學(xué)公式模擬出復(fù)雜的海面起伏的效果。并且這種統(tǒng)計(jì)海波算法可以表示為FFT的形式。因此,采用這種算法,可以快速的將各種不同頻率的波混合疊加在一起,產(chǎn)生具有更加復(fù)雜行為的波,這樣就可以模擬出非常逼真的海面效果。 在光學(xué)建模方面,本文改進(jìn)了HDR算法和基于紋理動(dòng)畫(huà)的Normal Mapping算法,并提出了將多種光學(xué)效果融合的計(jì)算公式,提高了海面的光效真實(shí)感。 在大規(guī)模海面場(chǎng)景的管理方面,通過(guò)對(duì)渲染流程的改進(jìn),實(shí)現(xiàn)了對(duì)海面場(chǎng)景管理的特殊性要求。可以對(duì)海面、海底場(chǎng)景進(jìn)行正確的裁減,減少不必要的渲染,提高渲染速度。 此外,通過(guò)在原創(chuàng)的三維圖形引擎中將上述算法實(shí)現(xiàn),得到了相應(yīng)的實(shí)驗(yàn)結(jié)果。應(yīng)用證明上述算法很好地滿足了虛擬海面的實(shí)時(shí)漫游的需要。 最后,對(duì)海面實(shí)時(shí)渲染的算法進(jìn)行小結(jié),并提出了改進(jìn)建議以及進(jìn)一步的展望。
[Abstract]:With the continuous development of computer hardware and software technology, 3D graphics engine technology has gradually become one of the main research content of computer graphics. It in virtual reality, digital city, television advertising, various computer aided design and scientific visualization plays huge role. With the computer simulation of natural phenomena is the key technology of 3D graphics engine. Natural scenes have complex shapes, random variation characteristics, difficult to express and study with the mathematical model. And the simulation of the flame, cloud, rain and other natural mountains and compared to the phenomenon, the sea movement rules of complex optical properties and makes simulation of the ocean is more challenging.
In this regard, this paper studies the current situation at home and abroad, in-depth study on geometric modeling and optical modeling of the sea, and improve the scene management of ocean surface grid generation technology and large scale on the sea. The optimization algorithm for large scale ocean rendering steps and large-scale sea surface which gives the scene management.
In geometric modeling of sea surface, with projected grid current LOD algorithm as the starting point, to construct the limit projection grid sampling accuracy, this method improves the algorithm in the old view close to water surface when the sampling frequency is increased sharply, the density of sample points due to surface mesh unsmooth, well with fast Fu Liye transform (FFT) algorithm to generate the surface combination. At the same time the algorithm has to a certain extent reduce the triangles projection of the grid, improve the rendering efficiency.
In the generation of the sea surface height, after the in-depth analysis and research of various documents, the use of marine statistic formula to simulate the complex effect ofshifting. And this formula can be expressed as the form of FFT. Therefore, using this algorithm can fast wave superposition of different frequency mixed together, to generate more complex behavior wave, this can simulate more realistic surface effect.
In terms of optical modeling, this paper improves HDR algorithm and Normal Mapping algorithm based on texture animation, and proposes a formula to integrate multiple optical effects to improve the effectiveness of sea surface.
In the management of large-scale sea scene, through the improvement of rendering process, we have realized the special requirement of sea scene management. We can correctly cut down the sea surface and submarine scenes, reduce unnecessary rendering and improve rendering speed.
In addition, through the implementation of the above algorithm in the original 3D graphics engine, we get the corresponding experimental results. The application proves that the algorithm can well satisfy the need of real-time roaming of virtual sea surface.
Finally, the algorithm for real-time rendering of the sea surface is summarized, and the suggestions for improvement and further prospect are put forward.

【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2009
【分類(lèi)號(hào)】：TP391.41

【引證文獻(xiàn)】

相關(guān)期刊論文 前1條

1 馮玉芬;;基于虛擬現(xiàn)實(shí)技術(shù)的動(dòng)態(tài)水面仿真方法研究[J];唐山師范學(xué)院學(xué)報(bào);2012年02期

相關(guān)碩士學(xué)位論文 前2條

1 孫磊;圖形引擎中大規(guī)模海洋的實(shí)時(shí)渲染與交互技術(shù)研究與實(shí)現(xiàn)[D];電子科技大學(xué);2011年

2 蔡麗麗;基于GPU的鉆井虛擬仿真中特效技術(shù)研究[D];東北石油大學(xué);2012年

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本文編號(hào)：1649620