Global and local deformations of solid primitives
Global and local deformations of solid primitives
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DOI：
10.1145/280811.280998
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发表时间：
1984-01
期刊：
影响因子：
--
通讯作者：
A. Barr
中科院分区：
文献类型：
--
作者：
A. Barr
开发了新的分层实体建模操作，其模拟几何对象的扭曲、弯曲、变细或类似的变换。其主要结果是，任意变形光滑曲面的法向量可由未变形曲面的法向量和变换矩阵直接计算。变形很容易在层次结构中组合，从简单的对象创建复杂的对象。简单对象中的位置向量和法向量用于计算更复杂形式的位置向量和法向量;变形层次中的每个级别都需要额外的矩阵乘法来计算法向量。变形是重要的和高度直观的操作，它简化了控制和渲染的大型家庭的三维几何形状。
New hierarchical solid modeling operations are developed, which simulate twisting, bending, tapering, or similar transformations of geometric objects. The chief result is that the normal vector of an arbitrarily deformed smooth surface can be calculated directly from the surface normal vector of the undeformed surface and a transformation matrix. Deformations are easily combined in a hierarchical structure, creating complex objects from simpler ones. The position vectors and normal vectors in the simpler objects are used to calculate the position and normal vectors in the more complex forms; each level in the deformation hierarchy requires an additional matrix multiply for the normal vector calculation. Deformations are important and highly intuitive operations which ease the control and rendering of large families of three-dimensional geometric shapes.