Is there a Bug in the number of Nulls produced in the CCX component

Hi David,

Please can you have a look at the attached file and see if my understanding of the amount of Nulls is correct.

Taken from a Thread: http://www.grasshopper3d.com/forum/topics/curve-curve-intersection?...

Attachments:

StreetIntersections_bug.gh, 12 KB

Replies to This Discussion

Permalink Reply by David Rutten on April 22, 2012 at 7:13am

That's one ugly data tree.... I doubt it's correct. Digging now... I'll let you know what I find out once I hit the K-T boundary.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Michael Pryor on April 22, 2012 at 12:11pm

Also I came along something similar with CCX. In this example when I used CCX I was getting an odd data tree and it was skipping some intersections, yet when I extruded one of my curve inputs and used BCX instead it worked fine.

Attachments:

gridfromlines (1).3dm, 492 KB
test delaunay mesh to nurbs.gh, 15 KB

Permalink Reply by Andrew Heumann on April 22, 2012 at 9:18am

Sorry to piggyback on this thread, but I thought I'd bring it up while you're digging into the tree structure of intersection results. Forgive me if this is something I've complained about before.

It seems to me that the default behavior around trees and nulls is in general fairly counter-intuitive. I can't think of any situation where having the nulls in {A;B} and the successful intersections in {A;B;C} would be useful. I always end up having to resort to any number of weird tricks to get them to line back up. If I want the same definition to work with different inputs, where in some cases only valid intersections are produced, and in other cases certain intersections fail, I'd like to be able to count on the data trees being consistent, whether they contain nulls or not. It would make a lot more sense to me to have the results from an intersection always go to the same branch, whether or not the result is valid.

Here's a more concrete example. Say I have a definition with some curve intersections and I want to label the intersections of the curves. When all intersections occur, the labeling works fine, since the paths all match up. However when some intersections fail, everything goes haywire, and the data tree of the intersection results needs some major coercing + manipulation in order to get it to match the structure of the labels.