| 摘要 |
<p>A fly-through, three-dimensional CAD system is provided. Computational requirements are bounded, by defining bounded volume or world (320) defining the volume to be displayed. Preprocessing data (316) assists in organizing data for high performance display (338). Full detail rendering is available. However in some situations, such as during fly-through, some or all portions are rendered in a simplified fashion (346), to maintain a high frame rate (356). The volume-based simplification involves rendering faces of cells or collections of cells which are at least partly intersected (326) by components of the system displayed. A plurality of granularities, preferably organized as an octree, provide multiple levels of detail. Unnecessary rendering load is reduced by view frustum culling (348) and considering certain cell face occlusion situations. For scene rendering, preferably slicewise, the detail level for slices is adjustably based on predictions of time-to-complete, to meet a frame rate target (356).</p> |
