发明名称 |
Method and system for computing the intersection of a bounding volume and screen-aligned plane |
摘要 |
Apparatus and methods are provided to perform volume rendering via composited texture-mapped convex polyhedra. This is accomplished by generating a sequence of z polygons defined by the intersection of a sequence of z planes parallel to the view plane with the convex polyhedron. The vertices of the convex polyhedron are numbered sequentially based on z-axis depth and this defines a sequence of slabs that are bounded by z planes intersecting the vertices. The edges of the convex polyhedron are numbered based on viewing the polyhedron along an axis from the closest vertex to the furthest vertex. A data structure maintains a list of active edges for each slab, where an edge is "active" if the edge intersects any z plane in the slab. Each vertex in the z polygon is defined by the intersection of an active edge with the z plane. The z polygon is rendered by connecting adjacent vertices, where the ordering is determined by the order of the active edges in the slab. Each edge of the z polygon can be rendered by performing only three multiplications, two additions, and one subtraction. These computationally efficient methods make volume rendering via texture mapping feasible.
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申请公布号 |
US6628281(B1) |
申请公布日期 |
2003.09.30 |
申请号 |
US20000513817 |
申请日期 |
2000.02.24 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION |
发明人 |
FOSSUM GORDON C.;D'AMORA BRUCE |
分类号 |
G06T15/40;(IPC1-7):G06T15/40 |
主分类号 |
G06T15/40 |
代理机构 |
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