# Geometry.DoesIntersec doesn't work well

**URL:** <https://forum.dynamobim.com/t/geometry-doesintersec-doesnt-work-well/62103>\
**Category:** Geometry\
**Tags:** revit, geometry, dynamo\
**Created:** [March 25, 2021, 9:19am UTC](https://forum.dynamobim.com/t/geometry-doesintersec-doesnt-work-well/62103 "2021-03-25T09:19:48Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![j.mellan](https://avatars.discourse-cdn.com/v4/letter/j/65b543/32.png) [@j.mellan](https://forum.dynamobim.com/u/j.mellan)\
**Post date:** [March 25, 2021, 9:19am UTC](https://forum.dynamobim.com/t/geometry-doesintersec-doesnt-work-well/62103/1 "2021-03-25T09:19:48Z")

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Hello there,

I’m struggling with a bloc that doesn’t work as intended.

My goal is to join lines created in Dynamo from the center of a geometry (Objects that i want to transform in Walls), to use Wall.ByLine atfer.  
It’s work not that good because lines aren’t joined, so wall aren’t joined either.

To know which lines I need to extend/join, I create circles (Diameter of wall width) at the start and end of lines, in order to check which circles intersect each other to get index of lines I need to join.

I have a list of circle that I group by key.

 ![image](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/0/0/003a01db18d15110490851d31f9d04a65f1b9505.png)

Then I use Geometry.DoesIntersect with a cross product, in order to get index of _true_.

My issue is that this works only with one list, not with a list of list. And because I don’t know how many sublist i could have in the futur, i can’t do this manually…

Is there a method to bypass this node ? I couldn’t figure it out until now.

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<div class="post-metadata">

**Author:** ![j.mellan](https://avatars.discourse-cdn.com/v4/letter/j/65b543/32.png) [@j.mellan](https://forum.dynamobim.com/u/j.mellan)\
**Post date:** [March 25, 2021, 9:22am UTC](https://forum.dynamobim.com/t/geometry-doesintersec-doesnt-work-well/62103/2 "2021-03-25T09:22:12Z")

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The node that doesn’t work (sorry, counld’t insert 2 pictures in my post) :

 ![image](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/0/5/058e542eda0e724d036a23ec2b00512df8ecaf66.png)

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<div class="post-metadata">

**Author:** ![shivaling](https://avatars.discourse-cdn.com/v4/letter/s/35a633/32.png) [@shivaling](https://forum.dynamobim.com/u/shivaling)\
**Post date:** [March 25, 2021, 5:26pm UTC](https://forum.dynamobim.com/t/geometry-doesintersec-doesnt-work-well/62103/3 "2021-03-25T17:26:53Z")

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Hi, instead of intersecting with circle, try creating a solid sphere or surface from circle (if all circle are in same plane) and check again for intersection.