Hi Strube,

> But what I was suggesting, and I still think that is very intuitive for users, is, adding a
> point on the hull and the curve just remains as fixed as possible. Especially because,
> even though it is a bit emberassing I haven't read the manual properly, using mode 2
> right now you cannot decide where on the hull you get a point.

The problem is I don't know of any way to make something like what you're describing work... - it's kind of a fundamental side effect that you can either keep the control points in their current location and have the curve shape change, or have the curve stay the same shape and have the control points shift around with some refinement in the general area you want to add detail (the second mode)...

I don't know how it would be possible to make things work to put in a control point in a specific location but then change the other points around to keep the curve the same shape, there just isn't any established mechanism that I know of that can be done to a NURBS curve to get that particular behavior...

The second mode that I describe above is often called a called "knot insertion" operation for NURBS curves - it's a way to refine the curve but keep the curve in its exact same current shape.

- Michael

Hello Michael,

the steps one needs to make after inserting a point in the "polygon hull line" in order to get (almost) the same curve back you had before inserting a new point seem to be the same every time.

I have made a lot of images and hope they make sense. The last one makes me think the points can also be calculated. (The red point is the position where the new point was inserted in the original curve's hull line and the locked, grey original curves are never hidden.)

Hi Strube, I think that you may be dealing with a special case there with some properties of a single span curve which won't necessarily translate the same way to a curve made up of more points...

I'm not sure how to make your process work for adding in a point here for example:




- Michael

But it can be done! (Green points' position was changed and the new construction line is (obviously) the curve's tangent at the point where it intersects with the hull line before inserting the point.)

Hi Strube, but what rule are you following to generate the green points, are you just tweaking them until you find a good match?

In order for it to be done automatically by MoI, it probably needs to go through a fully automated process.

I'm not sure how your method works, one thing that confuses me is some of your green points are on the original hull and some are on that tangent line. Also in an area where there is not an inflection the added control point will not intersect the curve as it is doing in this case.

- Michael

Should I accidentally find a solution (playing around with GH since my math knowledge isn't top notch) I let you know.