| OCR Text |
Show 71 Bezier 1. 2. out pointed The defined two drawbacks cannot have curve The shape of the a vertical depends curve of this of represent ation: tangent. the on method orientation of the coordinate axes. In order to avoid these two of of the curve is represented a curve in which t is To . is preferred. a parameter define the inconveniences, a parametric With the parametric representation, representation point a on an arc by the expression: . four vectors a, b, c, and d, the f?"owing conditions must be satisfied: 1. t is equal to zero '2. t is 1 at the final 3. those equal to at the' initial point. point. The values of the coordinates of the In this parametric at the derivatives of the initial and final curve points, at the end well as as points need to be given. vector which representation, the parametric derivative is is tangent the curve, but not The information for the computation of the tangent. is not available from the In be to the supplied of case for a polygonal a by represented simply by the direction length of the tangent of the vector model. mathematically defined model, additional conditions' non-linear a interpolation scheme. However, even can with this |
