Hi!

Does anybody know, how to create curve based on 9 points. I have XYZ coords
of 9 points and is there any formula which will connect them smoothly?
I tryed to use Bezier-curve, but it generate not what I need.
I think there will be algo. May be there is algo which connect 3 or 4
points?

--

- Ivan V.

- ICQ# 781487

Quote:> Does anybody know, how to create curve based on 9 points. I have XYZ
coords
> of 9 points and is there any formula which will connect them smoothly?
> I tryed to use Bezier-curve, but it generate not what I need.
> I think there will be algo. May be there is algo which connect 3 or 4
> points?

Natural cubic splines is one possibility.  I have an
implementation at
http://www.magic-software.com/Source/Curve3D/Curve3D.html

--
Dave Eberly

http://www.magic-software.com
http://www.wild-magic.com

> Hi!

> Does anybody know, how to create curve based on 9 points. I have XYZ
coords
> of 9 points and is there any formula which will connect them smoothly?
> I tryed to use Bezier-curve, but it generate not what I need.
> I think there will be algo. May be there is algo which connect 3 or 4
> points?

> --

>  - Ivan V.

>  - ICQ# 781487

If you want smooth interpolation of points, you could have a look at
Kochanek-Bartels or Catmull-Rom splines. Both use the Hermite
basis functions to do the actual interpolation; the tangent vectors
for each control point are aquired from the 4 control points that
make up a single curve-segment. I believe Dave Eberly wrote a paper
on them for use in keyframe interpolation. Can't remember what it's
called though..

Willem

Big thx to all!

I found what I need at
http://www.magic-software.com/Source/Curve3D/Curve3D.html

Thx to Dave Eberly!

--

- ? .

- ICQ# 781487

> Hi!

> Does anybody know, how to create curve based on 9 points. I have XYZ
coords
> of 9 points and is there any formula which will connect them smoothly?
> I tryed to use Bezier-curve, but it generate not what I need.
> I think there will be algo. May be there is algo which connect 3 or 4
> points?

> --

>  - Ivan V.

>  - ICQ# 781487

Hi,
I have a sine wave modeled in form of a Bezier curve and I want to find
out the point on the curve where the shape of the curve changes shape i.e
the point where the curve becomes concave if it is a convex curve earlier on
Someone suggested that I find the point where the curvature of the curve is
zero or use the second derivative of the curve has a very small value
like .01 something like that but I can not figure the basis for this reason.
What I was thinking about was to find that point on the curve where the
normal vector changes its direction but is this the only way ??
Does someone know of a better way???
Thanks in advance. Any help will be appriciated
sanjeev Gupta

Any help will be appriciated