- From: Max Froumentin <masmef@maths.bath.ac.uk>
- Date: 26 Mar 2000 16:37:37 +0100
- To: www-svg@w3.org
From the svg requirements: Paths can be made up of any combination of the following: - [bezier segments] - No other curve types (Other curve types such as splines or NURBS are either technically very difficult, industry-specific and/or have not established themselves as industry standards as much as beziers) I know it's probably futile to try and reopen the debate on basic shapes or paths, but it seems to me that having rational beziers wouldn't have been so "technically difficult", as they require only one extra parameter for each control point, and the computations for displaying them differ very little from non-rational beziers. The main advantage is that almost all standard types of parametric curves can be represented (not approximated) by rational bezier: B-splines, NURBS, beta splines, you name it. The only problem I can see for paths is that rational bezier don't necessarily interpolate their end control points. But I think that would have been a minor issue since an SVG renderer could always connect loose ends with line segments. My second point is about transformations: transformations can be represented by a 3x3 matrix (section 7.4): [a c e] [b d f] [0 0 1] <- why isn't it possible to modify this row? Being able to change the leftmost 2 values would allow nice perspective effects on objects, e.g. scrolling text à la Star Wars. Max. -- Max Froumentin - http://www.bath.ac.uk/~masmef Department of Mathematical Sciences University of Bath Bath BA2 7AY United Kingdom
Received on Sunday, 26 March 2000 10:37:45 UTC