The Essentials of CAGD

| 1. | Evaluate the curve in Example 10.2 at the midpoint of [ u 3, u 4] by sketching the polygon, intermediate control points, knot sequence, and the spans involved in each step of the de Boor algorithm. There is no need to compute numbers. |
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| 2. | What is the multiplicity vector for the following knot sequence If this knot sequence belongs to a quadratic curve, how many segments are there? How many are there if the knot sequence belongs to a cubic curve? |
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| 3. | What is the derivative at u = 1.5 of the B-spline curve from Example 10.5? |
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| 4. | What is the derivative of the same curve at u = 0? |
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| 5. | Consider the knot sequence 0, 0, 3, 4, 6, 6. Sketch the B-spline N 2 2. (Hint: First, find the Greville abscissae.) |
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| 6. | Over the knot sequence 0, 0, 0, 3, 4, 6, 6, 6 sketch N 3 1. |
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| 7. | Using the knot sequence from Exercise 5, write the function y = 3 u as a quadratic B-spline function. |
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| 8. | Write the function y = 3 u as a cubic B-spline function with knot sequence 0, 0, 0, 3, 4, 6, 6, 6. |
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| 9. | The first and second derivative formulas for a B-spline curve in (10.11) and (10.13) follow a particular pattern. In the same manner, write down the third derivative. How would this be implemented via the de Boor algorithm? |
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| 10. | List the condition(s) for... |