Adding and Filtering data, based on attributes

Hello everyone,

Is there a way to add attributes to geometry - point/ curves ( like name, location/ area name, land-use type and others) and then filter them on the basis of these assigned attributes, like choosing curves with certain land-use type, or selecting curves from a certain area ( i know this can be done with containment component) but i want to base the selection using attributes

Replies to This Discussion

Permalink Reply by David Rutten on June 12, 2012 at 2:02pm

Hi Khizer,

I began adding user data support for Grasshopper data a while back, but I removed it again when I ran into two problems I couldn't solve, to wit:

It was necessary for component developers to handle user data, which meant they could no longer use simple types such as Point3d or System.Int32, but instead had to always use the Grasshopper wrapping types, which is a major pain in the *ss.
It is unclear what needs to happen to userdata when there is a conflict. Say for example you intersect two curves. One has UserData attached to it marking it as "Site=A", the other one is associated with "Site=K". What user data (if any) should the intersection points have? Both? Neither? User specified? What would the UI look like.

The good news is that both problems may disappear with a single solution. If I can figure out how to transfer user data from inputs to outputs then I do not have to make component developers responsible for doing this.

David Rutten

david@mcneel.com

Poprad, Slovakia

Permalink Reply by Luis Fraguada on June 12, 2012 at 3:15pm

Interesting :)

Permalink Reply by Khizer Ishtiaq on June 13, 2012 at 3:54am

Woah... This sounded very simple turns out to be a complex issue.

"One has UserData attached to it marking it as "Site=A", the other one is associated with "Site=K". What user data (if any) should the intersection points have? Both? Neither? User specified?"

This is a very interesting question since it would be difficult to generalize. However, i feel in most cases it would be appropriate to assign the derived data to child geometry inherited from the parent interacting geometries. Say when intersecting Curve "Site=A" and "Site=K" the interaction points have Point "Site=AK" or "Site=A,K"

Then again, what if there is already user data "Site=AK"?

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