Line Points Coordinates

Replies to This Discussion

Permalink Reply by Joseph Oster on March 13, 2017 at 5:21pm

Try the VB, C# and Python Coding forum.

http://www.grasshopper3d.com/forum/categories/vb-c-and-python-codin...

Permalink Reply by David Rutten on March 14, 2017 at 3:25am

Is this a scripting question?

Permalink Reply by Robert D. Vochescu on March 14, 2017 at 4:16pm

Yes.

Permalink Reply by Robert D. Vochescu on March 14, 2017 at 4:16pm

ok.

Thank you for answering. Next time i will post there.

Robert

Permalink Reply by David Rutten on March 14, 2017 at 3:28am

Surely the end-point of one of the lines is the same as the start-point of the other line?

All coordinates in GH are global, in that they are all specified with respect to WorldXY. Grasshopper doesn't have local c-planes like Rhino.

You can extract the end-points (both end-points) from a set of curves, then merge them all into a single big list of points and use the [Cull Duplicates] component to remove points that are too close together. You can specify the tolerance here, so even if your curves aren't exactly coincident at their ends, you can still make it work.

Permalink Reply by Robert D. Vochescu on March 14, 2017 at 3:56pm

Hi David,

Thanks for answering. Is a question for a c# component i'm writting. Ok I understand. The problem was also in my code. I used:

double m_Length = m_Beams[i].Length;

Point3d m_Start = m_Beams[i].PointAt(0);

Point3d m_End = m_Beams[i].PointAt(Length);

and this work bad. Why? Now i discovered:

Point3d m_Start = m_Beams[i].From;

Point3d m_End = m_Beams[i].To;

thant works very good.

Thank you.

Robert

Permalink Reply by Robert D. Vochescu on March 14, 2017 at 4:15pm

Hi David,

Another question. CullDuplicate can be very usefull to me, but I see that is a Grasshopper component (Component Index>Vector>Point>Cull Duplicates). I need something similar to use in C# code. Can you give me some advices?

Thanks

Permalink Reply by David Rutten on March 14, 2017 at 5:15pm

I think it uses the Grasshopper.Kernel.Geometry.Node3Tree class to perform quick nearest neighbour searches. You can use the same class in C#, but it'll require you to populate the tree and loop the searches.

If you know your end-points are always exactly coincident, or if you know they are always exactly coincident after rounding to N decimal places, you can ditch the Node3Tree and just perform exact lookups. Either using a HashSet, or Dictionary or some other collection class with O(1) or O(log N) lookup.