Move along path at set speed

vvvv beta general
1

Hi, does anyone know how to move an object along a path at a set speed.

i.e. the further the ball, the longer it takes to get there. , and vice-versa.

spheres.zip (5.2 kB)

2

hi,
i once also needed a B-Spline with “arc length parameterization”. So i needed a spline where i can specify the distance from the beginning of the spline - measured along the curve.

i did this patch which made it closely to a module but not yet.
so have please a try.

it is thought to work like that:

  • put it ontop of your b-spline node and connect its output to the input of the b-spline.
  • use the same output room for arc length like the input room for the b-spline. use 0…1 for now.
  • use the same topology (open is tested and works)
  • use the same control points
  • use the same degree

what ArcLength does is:
you put in a position on the curve (arc length parameterized) and this module calculates back what position on the curve (related to “input room”) the original b-spline module needs to finally get to that position.

hope that works for you…

ArcLength.v4p (22.5 kB)

3

hey gregsn,

wondering if you used Differential (Spreads) instead of CDR (Spreads) minus CAR (Spreads) :
wouldn’t it do the same?

4

you are totally right kalle. you see why it is not a module yet?! ;)