Flipped curves

I encountered a change in the way grasshopper flips curves (from version 8.0066 to version 9.0014). It appears that the guide curve doesn't work properly any more.

In the screenshot above, there are two curves. I flip Crv1 with Crv2 as guide, here grasshopper flips the curve.

But when I flip Crv2 first and then put it in as guide curve, grasshopper still flips Crv1.

Am I doing something wrong or is this a bug?

Attachments:

flip.PNG, 47 KB
flipped curves.gh, 5 KB

Replies to This Discussion

Permalink Reply by Reino on December 12, 2012 at 2:41am

Thanks for your reply. I have had a look at that case, but my problem is not related to the one you are referring to, since there are no guide curves being used at all.

What I am after is that the curve that I want to flip will get the same direction as the 'guide curve' after using the flip-component.

Permalink Reply by Reino on December 19, 2012 at 12:47am

I think I know the reason why my guide curve doesn't work. In my example I used a line as guide curve, I think in 0.9 it depends on the curvature so in which way it rotates, as a line doesn't have a curvature it cannot find its direction.
Am I right my reasoning?

Permalink Reply by David Rutten on December 19, 2012 at 4:11am

Probably. I need to make the guide logic better to also take into account linear directions.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by David Rutten on December 20, 2012 at 12:08pm

I added extra smarts to the Guide curve interpreter. If the guide is linear (meaning if it deviates less than one percent of its length from the line connecting the guide end-points) then different flipping logic is used. In these cases the only thing that matters is the end-points of the curve and whether they are pointing in the same direction as the guide. If the guide is closed or not linear to within 1% then the clockwise/counter-clockwise orientation of the guide is used to determine flipping.

Unfortunately I have a draw a line in the sand somewhere (at 1%) which means the flipping behaviour is no longer continuous. Also, it is now no longer possible to flip a closed curve if you supply a linear guide.

Still, I'm hopeful that the new behaviour better approximates what people expect.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Reino on December 21, 2012 at 12:12am

Ok, thanks!
With a proper working guide curve the Flipcurve component is quite powerful.

PS. When can we expect this new release?

Permalink Reply by David Rutten on December 21, 2012 at 2:06am

Probably quite a while unfortunately. This was supposed to be a good clean development period but as it turns out I'll be very busy in the upcoming months moving to a new country/house. Given how bad I am at prediction release dates even without major external factors I hesitate to commit to anything now.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Michael Pryor on February 24, 2013 at 7:20pm