標題: 用於區塊繪圖之階層式儲存方式設計
A Hierarchical Primitive List for Tile-based Rendering
作者: 蕭之傑
Hsiao, Chih-Chieh
鍾崇斌
Chung, Chung-Ping
資訊科學與工程研究所
關鍵字: 繪圖處理器;區塊繪圖;階層式三角形列表;區塊;三角形列表;Graphics Processing Unit;Tile-based Rendering;Hierarchical Primitive List;Tile;Primitive list
公開日期: 2008
摘要: 在現今嵌入式系統中(如:手機、個人導航裝置等)往往資源相當受 限。而具備分區塊式繪圖 (tile-based rendering)特性的繪圖處理器,在 此類應用中相當常見,其一次只處理畫面上的一個區塊,而非整個畫 面,故其處理一個區塊所需的區塊深度緩衝器(Tile Z-buffer)及區塊畫 面緩衝器(Tile frame buffer)只需與區塊大小相同即可,而非整個畫 面。故傳統繪圖處理器中時常被重覆存取之深度緩衝器及畫面緩衝 器,即可很容易的被整合至晶片中來有效降低對外部記憶體之存取。 然而傳統的非階層式三角形名單之分區塊式繪圖處理器設計中,會在 場景複雜度增高時,增大對儲存三角形列表之記憶體空間需求。在本 論文中,將修改分區塊式繪圖處理器中記錄區塊中所屬三角形的動作 (tile binning),使其能依據三角形不同邊界方框之大小、形狀及位置 決定存放在何種階層的三角形列表中,能使用較少之三角形名單來記 錄。並提出一個整合式的判斷方法,同時可以整合多種不同階層,且 不論畫面中有何種三角形之邊界方框,都能以固定的判斷次數來選定 三角形該被放在哪一個階層中。而此判斷方法也能很輕易以簡單的硬體來實現,進而減少其判斷所需的時間。透過這些修改,讓此種繪圖 處理器能在畫面複雜度不斷增高時,也能針對不同具有不同大小、形 狀及位置的三角形之邊界方框做最有效的判斷,進而減少整體儲存三 角形名單所需之空間。
Tile-based rendering has been widely used in resource-limited graphic processing environments, e.g., for hand-held devices. Since large primitives may cover a significant number of tiles, they need to be recorded in the primitive lists of all related tiles. We propose a hierarchical primitive lists structure, which also copes with misaligned and non-square primitive problems, to minimize the primitive recording. Intended advantages include: reduced storage pressure, list building time, primitive retrieval counts for subsequent rendering, and primitive data accesses from external memory during rendering, and possibly enhanced data locality/resource utilization if layer-based rendering is exploited. Based on this structure, we propose a primitive-hierarchy fitting (hardware) algorithm which, for a given primitive of any size and shape, determines a best way of storing it in the structure. Experimental results on Doom3 and Quake4 show a 73% storage reduction using only square hierarchies or 78% with our full capability, compared with flat tile-based lists.
URI: http://140.113.39.130/cdrfb3/record/nctu/#GT079655607
http://hdl.handle.net/11536/43413
Appears in Collections:Thesis


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  1. 560701.pdf