Please help, problems with curves

Please help, problems with curves

Post by é×á? ÷ » Mon, 09 Apr 2001 00:58:52



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?
Please help!

--

 - Ivan V.

 - ICQ# 781487

 
 
 

Please help, problems with curves

Post by Dave Eberl » Mon, 09 Apr 2001 03:46:46



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

 
 
 

Please help, problems with curves

Post by Willem H. de Boe » Tue, 10 Apr 2001 17:10:25




> 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?
> Please help!

> --

>  - 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

 
 
 

Please help, problems with curves

Post by é×á? ÷ » Wed, 11 Apr 2001 03:26:56


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?
> Please help!

> --

>  - Ivan V.

>  - ICQ# 781487

 
 
 

1. finding a point where a BEZIER/NURBS curve changes shape-help please

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

2. Antialiasing bezier curves

3. Help with curved text please

4. real explosion plugin???

5. Help with curves please

6. Corel Draw/standard file formats?

7. Tool for drawing curves (help please)

8. Trying to curve text around a circle please help

9. Param Curve Question (Please Help)

10. Please, please help - problem rendering a flc in 3ds4

11. Quadratic Curve Derivatives help, Please

12. Help Smoothing bezier curves please