| 摘要 |
A 3D scientific visualization system for viewing models composed of polyhedra or other elements having vertices at which analysis results (e.g., temperature or pressure) are defined. The model is viewed either in a cutting plane or as a contour surface in which a given result assumes a specified value. Polygons making up an intersection surface formed by the intersection of the cutting plane or contour surface with the polyhedra forming the model are generated and passed to a polygon processor for rendering and display on a raster-scan device. A series of intersection surfaces are generated for display by varying either the position of the cutting plane along its normal or the value that the result assumes on the contour surface. The testing of elements for possible intersection by the cutting plane or contour surface is speeded up by presorting the elements into zones, based upon either the position of each element along the cutting plane normal or the value of the result over the vertices of the element, and testing only elements within certain zones for intersection with the plane or surface. Intersection calculations for edges shared by multiple elements are minimized by maintaining a global list of edges and flagging those edges whose intersection point with the cutting plane or contour surface has been calculated for any element of the model. The outer surfaces are identified for viewing in an alternative mode of operation by counting the elements sharing a given face of the model and flagging as outer faces those faces associated with only a single element.
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