DeFi

03 March 2008, 10:56 AM

Hello,

I'm trying to animate a character with a tail using spline IK. The tails curves need to be as smooth as possible but easy to animate, so I took a spline with not too many control points. Unluckily, if set to smooth, the splines curvature is not as smooth as i want it to be. Setting the points to bezier enables me to optimize the curvature, but the the spline can not be animated without looking totally wrong in other positions. So I tried to use a NURBS point curve instead. It had a nearly perfect curvature.

http://www.defi1.de/splineIK/curves.jpg

red = spline with smooth points

yellow = NURBS point curve

The problem with the NURBS curve was, that it made the whole bone chain wobble when moving single control points, thus making animation of the curve impossible.

Is there a way to obtain an automatically smoothed curve that at least mimics globally minimizing the curvature like NURBS does and doesn't mess up when animating the curve points? I'm posting this in the scripting forum, because some people here (like eek) know the math behind NURBS, b-splines and bezier curves and I have a feeling that this problem can only be solved by scripting and math or even writing a plugin in c++.

Greetings

DeFi

I'm trying to animate a character with a tail using spline IK. The tails curves need to be as smooth as possible but easy to animate, so I took a spline with not too many control points. Unluckily, if set to smooth, the splines curvature is not as smooth as i want it to be. Setting the points to bezier enables me to optimize the curvature, but the the spline can not be animated without looking totally wrong in other positions. So I tried to use a NURBS point curve instead. It had a nearly perfect curvature.

http://www.defi1.de/splineIK/curves.jpg

red = spline with smooth points

yellow = NURBS point curve

The problem with the NURBS curve was, that it made the whole bone chain wobble when moving single control points, thus making animation of the curve impossible.

Is there a way to obtain an automatically smoothed curve that at least mimics globally minimizing the curvature like NURBS does and doesn't mess up when animating the curve points? I'm posting this in the scripting forum, because some people here (like eek) know the math behind NURBS, b-splines and bezier curves and I have a feeling that this problem can only be solved by scripting and math or even writing a plugin in c++.

Greetings

DeFi