I'm quite a newbie at opengl and 3d math programming, i'm attempting to do a simple animation through a catmull rom spline, i did a quick attempt that works good on a simple ogl (jogl) test case i did, but not so good when i ported the algorithm to my worldwind based app.
Meanwhile i discovered that a correct representation of the spline is usually done via some parametrization functions, so i tried to study a bit of uniform parametrization (and i think i got it) and the arc length parametrization (i don't get it completely yet)
What am i currently missing is this: let's suppose i have a s(t) arc length parametrization already done, and a f(t) uniform parametrization.
Afaik, s(t) returns the arc length and by doing the inverse i can get the t factor. But, how do i get the point on the spline, when i know the arc length distance, i.e. how do i map s(t) and f(t) togheter?
just using the t retrieved by s^-1(arcLength) seems not correct by looking at this:
http://www.algorithmist.net/arclengthparam.html (page 5) since the two parametrization seems to define different points in the spline for the same t value
Surely i'm confused quite a lot, i can't neither find complete tuts or sample code so far i only got maths article but it's not so easy for me to port those informations into working code, so any help will be greatly appreciated.
Thanks in advance