4 then t4 t t5 and the control points that affect the

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: lt; t5, and the control points that affect the final position are P4, P3, P2, P1 Example • Assume we have a cubic B-spline whose knot vector is {0, 0, 0, 0, 0.25, 0.5, 0.75, 1, 1, 1, 1} • Let’s compute a point at t = 0.4 • Then, t4 < t < t5, and the control points that affect the final position are P4, P3, P2, P1 What if you want to edit some details? • You might want to add some high resolution details at a particular area while keeping the rest the same Knot insertion • We can do this by knot Insertion – increase the resolution for some area • New knots and control points can be added without changing the shape of the curve • Both the knots and control points are going to increase Knot insertion • For a curve of degree f, we remove f-1 points and add f points • i.e., for a cubic B-spline, remove 2 points and add 3 points Knot insertion • If the new knot t is inserted into the span [tj, tj+1), the new control points can be computed by where Qi is the new control p...
View Full Document

Ask a homework question - tutors are online