就飛行模擬系統而言，在低階個人電腦上即時的展示大區域地形模型是一個挑戰。在本論文的研究中，我們提出以漸進網格 (progressive meshes) 為基礎的動態載入式 (dynamic-loading) 視點相關 (view-dependent) 多重解析度模塑 (multiresolution modeling) 來達到這個目標。任意地形模型的漸近網格表示式可以定義出一序列的精細化記錄 (refinement records)。視點相關漸近網格的多重解析度模塑技術可以根據目前的視點參數 (view parameters) ，從這序列中選擇一些記錄來調整漸近網格中各區域的解析度。對於大區域地形模型而言，建構其漸近網格表示式是非常耗時的；而且通常記憶體並無法完全地容納全部的模型資料。因此，我們將大區域地形模型切分成許多矩形小地塊，並且動態地讀取所需的小地塊到記憶中來展示。另外，就飛行模擬的應用而言，我們建立一個控制介面來模擬戰鬥機的飛行，目的是要讓使用者感覺就如同他們正在地形上駕駛戰鬥機。 The real-time rendering of large terrain models on a low-level personal computer is a challenge for flight simulation. In this paper, a view-dependent multiresolution terrain modeling based on the progressive mesh (PM) with dynamic loading technique is proposed to achieve the purpose. The PM representation defines a continuous sequence of different-resolution approximate meshes for an arbitrary triangle terrain model. The view-dependent PM is a framework for selectively refining an arbitrary PM according to the current view parameters. For a large terrain model, constructing PM representation is very time-consuming; moreover, it is generally impractical to load the whole terrain model into memory. Thus, we partition a large terrain model into blocks and then dynamically load the necessary terrain blocks into the memory for rendering. For the application of flight simulation, we build a control interface to simulate the fighter’s action; let users feel as they are aviating the fighter over the terrain.
