Hi Michael

I thought I would post this 3dm and image. It could be bad modelling on my part somewhere but when using blend I end up with a rough edge which extends over the centreline and wont trim off.

Is that something that needs to be tuned up with blend ?

Hi Kevin, just part of how Blend works can make it this kind of issue happen when you've got tightly bending areas.

Blend tries to make things come off perpendicular from the edge curve and if the edge curve bends around in a small area it will make for a "bunching" type effect like this:



You can get a similar kind of bunching when trying to do a fillet around a tight corner that involves an offset like this:



It's sort of a fundamental problem with tightly bent shapes for construction techniques that involve coming off perpendicular from a curve.


In order to avoid it you'll need to make the cut away portion not have quite as tight of a bend right near the end.

I am planning on adding an option to Blend that will make it behave a bit differently than only coming off perpendicular from edges which could then help for cases like this.

- Michael

You can solve it.
Just extract isocurves from blend, repair them, then run LOFT (loose exact).

This is how I made:

Posted:Michael Gibson
In order to avoid it you'll need to make the cut away portion not have quite as tight of a bend right near the end.


Ok, thanks, thats a handy tip and thanks for technical explanation as to why the error is occuring.


Posted: Andrei Samardac
Just extract isocurves from blend, repair them, then run LOFT (loose exact).


That tip is gold, thanks Andrei
I just tried isocurves for the first time with loft->loose-exact and gives a great result for my purposes. I can see myself using this a lot to solve certain problems.

kevjon,
You are welcome)