Curve constructed from control points and interpolated points

Replies to This Discussion

Permalink Reply by Florian Frank on May 16, 2013 at 11:12am

Hi Dmitriy,

I don't know how this should look like....can you draw an example. Interpolated curve an ordinary Nurbs curve (control points) work in a completely different manner. The problem is where they meet. I've made a quick example with a blendcurve. So you can imagine.

If you can specify more i can give you some hints for your bastard curve ;-)

Cheers FF

Attachments:

• InterpolatedControlPointCurve.gh, 9 KB

Permalink Reply by Dmitriy Sonechko on May 20, 2013 at 7:55am

Hi Florian,

Thanks for having look at that.

Please refer to the image enclosed.

Here you see 2 curves: one as an input (control point based curve of degree 3). Second one is obtained by splitting the input curve with the point indicated in green and then joining both pieces together.

So I want my "bastard" curve to be defined as following:

- points indicated in blue should be given as control point input;

- point indicated in green - should be given as interpolated point;

- neighbor control points of interpolated one should be calculated automatically;

- not only 1-st derivative but 2-nd derivative continuity should be maintained.

I think knot insertion procedure would be required here but I am not sure with what sequence it should be implemented.

Thank you.

Dmitriy

Permalink Reply by Danny Boyes on May 20, 2013 at 8:51am

I've used this methodology before in GH similar to this.

Permalink Reply by Florian Frank on May 20, 2013 at 9:02am

Hi Dmitriy,

So you need a control point curve that goes trough a certain point, you want to set? Like in the example in the image below?
This could be done with knots (active points in the image).  The corners of the polyline are the control points of the actual curve. So instead of doing crazy shit with different curves and combining them this has a much more clean result.

Best regards,

FF