Advanced Graphics

Lecture 4 Index
...back to lecture 3
Part A: Bezier curves
Part B: B-splines
on to lecture 5...

4B) B-splines.

Why B-splines?

• minimise the order of the polynomial pieces
• maximise the continuity between pieces
• minimise the number of control points controlling a piece
• have positive basis functions
• have basis functions which partition unity, implying that each piece lies inside its control points' convex hull
• are invarient with respect to affine transforms

Exercises How many control points are required for a quartic B-spline? Why are cubics the default for B-spline use? Explain the difference between Uniform, Open Uniform, and Non-Uniform knot vectors. What are the advantages of each type?

Lecture 4 Index
...back to lecture 3
Part A: Bezier curves
Part B: B-splines
on to lecture 5...