研究生: |
劉詠蓁 Liu, Elvire |
---|---|
論文名稱: |
以路徑追蹤繪製可見光光譜的色散現象 Bidirectional Path Tracing for Dispersion of Visible Light |
指導教授: | 張鈞法 |
學位類別: |
碩士 Master |
系所名稱: |
資訊工程學系 Department of Computer Science and Information Engineering |
論文出版年: | 2021 |
畢業學年度: | 109 |
語文別: | 中文 |
論文頁數: | 27 |
中文關鍵詞: | 路徑追蹤 、頻譜採樣 |
英文關鍵詞: | Path Tracing, Spectral Sampling |
DOI URL: | http://doi.org/10.6345/NTNU202100234 |
論文種類: | 學術論文 |
相關次數: | 點閱:143 下載:9 |
分享至: |
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報 |
近年來,計算機圖學領域隨著 GPU效能的快速提升,光線追蹤自從多年前提出後快速進展成能夠實時呈現在大眾前的樣貌。我們將以CUDA 作為基礎,利用 GPU 的分散式運算引擎來更加高效率地解決光線追蹤這個較為複雜的計算。
光譜渲染器可以實現幾種在一般光線追蹤看不太到的特殊光學現象,例如散射和螢光。由於光譜渲染必須對光譜域進行採樣,由於採樣的成本高、計算量大,導致收斂速度非常差,在實際發射或反射光譜方面得到每增加採樣次數,計算量倍增的場景。我們提出針對材質改變採樣次數的非均勻採樣頻譜渲染:當光線打到折射材質時進行更多的射線採樣,這是一種簡單又有效果的方法。
我們建置了一組測試場景,由於我們的方法使用到非均勻光譜的處理,我們將所有場景位置形狀保持相同,對照組為均勻採樣,實驗組使用一組測量的非均勻的重要性採樣。
最後,我們對不同的頻譜採樣方式進行了比較,並發現我們的方法大大減少了均方誤差,在各種困難的情況下,只需很少的開銷就可以減少顏色噪音以及在原始經典的渲染器中的繪製。
Spectral renderers are capable of reproducing several advanced phenomena of light, such as chromatic dispersion and fluorescence.
The following paper will discuss our spectral render algorithm in CUDA, which is based on faster GPU parallel processing system. We construct a set of test scenes, as our method works on nonuniform spectra sampling, we keep all scenes geometrically identical, but vary material using sets of measured nonuniform reflectance spectra with importance sampling.
At as spectral renderers must sample the spectral domain, they are typically a drag on sampling issues leading to notably poor convergence rates, which are reinforced when reflectional materials are involved in otherwise simple scenes.
[Kaj 86] J. T. Kajiya. The rendering equation. In Proceedings of the 13th Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH’86, page 143–150, New York, NY, USA, 1986. Association for Computing Machinery.
[Lin 89] B. J. Lindbloom. Accurate color reproduction for computer graphics applications. In Proceedings of the 16th Annual Conference on Computer Graphics and Interactive Techniques, SIGGRAPH’89, page 117–126, New York, NY, USA, 1989. Association for Computing Machinery.
[Vea 97] E. Veach. Robust Monte Carlo Methods for Light Transport Simulation. PhD thesis, Stanford, CA, USA, 1998.
[WN 14] A. Wilkie, S. Nawaz, M. Droske, A. Weidlich, and J. Hanika. Hero wavelength spectral sampling. In Proceedings of the 25th Eurographics Symposium on Rendering, EGSR’14, page 123–131, Goslar, DEU, 2014. Eurographics Association.
[PM 16] Pharr, Matt and Jakob, Wenzel and Humphreys, Greg. Physically Based Rendering: From Theory to Implementation. Morgan Kaufmann Publishers Inc., San Francisco, CA, USA, 3rd edition, 2016.
Github, Nvidia, cuda-samples, https://github.com/NVIDIA/cuda-samples.
Nvidia Proramming Guide::CUDA Toolkit Documentation,http://docs.nvidia.com/cuda/cuda-c-programming-guide/indexhtml.
GTC 2014 C.Allen Waddle, S4433 Real-Time Spectral Rendering Tutorial, htpps://on-demand-gputechconf.com/gtc/2014/presentations/S4433-real-time-spectral-rendering.pdf.