透過三維圖像捲繞和解耦渲染降低雲端遊戲中的互動延遲

Interaction Delay Reduction in Cloud Gaming with 3D Image Warping and Decoupled Rendering

洪崇耀(Chung-Yao Hung)

指導教授 ： 簡韶逸

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.00732

摘要

隨著雲端技術發展，雲端遊戲將是未來的遊戲趨勢，透過雲端遊戲，玩家不需要購買高階的顯示卡和處理器，只需要一台低階的電腦、智慧型手機或是平板電腦，就可以隨時隨地玩想玩的遊戲並透過雲端將存檔資料同步，受限於頻寬與實時運算的限制，目前大多數的雲端遊戲服務只提供720P的解析度，但隨著4G 網路的發展頻寬將不再是問題。互動延遲在遊戲中是一個很嚴重的問題，越高的互動延遲會帶來較差的遊戲體驗並降低大眾對雲端遊戲的遊玩意願，互動延遲受限於伺服器和客戶端的節點距離，無法透過網路頻寬的增加而降低，3G網路的延遲相較於wifi以及有線的網路又更加嚴重，使得我們無法隨時隨地使用雲端遊戲服務，為了消除這樣的限制降低互動延遲是必須的。現今幾乎所有的行動裝置都配備了繪圖晶片，然而在目前得雲端遊戲服務中，繪圖晶片只被利用來顯示遊戲畫面串流的結果。在本篇論文中呈現了一套混合式雲端遊戲系統，將前景物體(可互動)與背景(非互動)分開，背景在雲端伺服器進行渲染，前景物體根據玩家的操作在客戶端渲染來降低互動延遲。每當玩家送出任意的控制訊號，背景會透過伺服器所送來的參照背景資訊利用三維影像捲繞的技術所得到，而前景物體會用客戶端的顯示晶片進行解耦渲染，來呈現出玩家控制後的影像結果，因此玩家不再需要等待漫長的網路傳輸時間就可以得到回應。在高網路延遲的環境下，相較於現今的雲端遊戲架構，本篇論文所提出的系統可將玩家進行高互動需求遊戲的遊戲平均意見分數從1提升到3.5。

關鍵字

雲端遊戲 ； 互動延遲

並列摘要

With development of cloud computing technology, cloud gaming has become the gaming trend in future. Limited to bandwidth and real-time constraint, most cloud gaming services can only provide 720p resolution. But with 4G network, bandwidth will not be a problem in future but interaction delay. Higher interaction delay make worse cloud gaming experience and lower people's will to use the service which make it a serious restriction. To eliminate the restriction, interaction delay should be reduced. Nowadays, almost all mobile devices are equipped graphic processing unit(GPU) for rendering. However, in current cloud gaming solution, GPU is only be used for displaying the frame got from video decoder. In this work, a hybrid solution for reducing interactive delay in cloud gaming is presented. This work separates background(non-interactive) objects and foreground(interactive) objects. Background objects are rendered on cloud server then send to client with corresponding depth map. Foreground objects are rendered by GPU in client according to player's control. When player sends any control signals, scene is made by 3D image warping with reference background information and decoupled rendering foreground objects by GPU on client. The long waiting time is no more required. In comparison to current cloud gaming framework, the Game Mean Opinion Score(GMOS)increase from 1 to 3.5 for highly interactive game genres in high network delay environment.

並列關鍵字

Cloud Gaming ； Interaction Delay

參考文獻

rendering contexts to enhance the real-time video coding for mobile cloud gaming,”

[3] NVIDIA Corporation, ,” http://www.nvidia.com/.

[6] Mark Claypool and Kajal Claypool, “Latency can kill: precision and deadline in

three-dimensional computer graphics,” Tech. Rep., 1997.

[9] S. Zinger, L. Do, and P. H. N. de With, “Free-viewpoint depth image based rendering,”J. Vis. Comun. Image Represent., vol. 21, no. 5-6, pp. 533–541, July 2010.