# DoesIntersection Problem **URL:** \ **Category:** Revit\ **Tags:** dynamo\ **Created:** [November 2, 2021, 12:04am UTC](https://forum.dynamobim.com/t/doesintersection-problem/69876 "2021-11-02T00:04:08Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Laura420](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/laura420/32/129127_2.png) [@Laura420](https://forum.dynamobim.com/u/Laura420)\ **Post date:** [November 2, 2021, 12:04am UTC](https://forum.dynamobim.com/t/doesintersection-problem/69876/1 "2021-11-02T00:04:08Z")
I split my top roof’s surface to two list: first list - surfaces parallel to axis x second list - surfaces parallel to axis y after DoesIntersection first list is intersection of first surface parallel to axis x with all surfaces parallel to axis y, by analogy second list is intersection of second surface parallel to axis x with all surfaces parallel to axis y ![obraz_2021-11-02_005836](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/1/c/1c1afa851879fa1c3677fcd79e928f3d2e309b54.png) Is it something wrong in my approach? Because in this example all surfaces have to have min two intersections. For surface number 0 with surface 1 and 10 (two intersections). Do you have any idea? ---
**Author:** ![honeyjain619](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/honeyjain619/32/121215_2.png) [@honeyjain619](https://forum.dynamobim.com/u/honeyjain619)\ **Post date:** [November 2, 2021, 6:41am UTC](https://forum.dynamobim.com/t/doesintersection-problem/69876/2 "2021-11-02T06:41:52Z")
This is a lacing problem or list structure problem. Currently you are getting , no. of surfaces intersect with Surface\_X if you wanna calculate no. of surface intersect with surface\_Y, then do this changes and add both the list (surface\_X & surface\_Y list) you will get total number of clash in each surface as per list. ![obraz_2021-11-02_005836](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/6/3/6327b6eab197908185300f700f61ae06e94b00ac.png) ---
**Author:** ![Laura420](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/laura420/32/129127_2.png) [@Laura420](https://forum.dynamobim.com/u/Laura420)\ **Post date:** [November 2, 2021, 10:23am UTC](https://forum.dynamobim.com/t/doesintersection-problem/69876/3 "2021-11-02T10:23:52Z")
![obraz_2021-11-02_112153](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/7/7/774bf49d39923ea5322779884d7605f53b1f3702.png) ---
**Author:** ![honeyjain619](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/honeyjain619/32/121215_2.png) [@honeyjain619](https://forum.dynamobim.com/u/honeyjain619)\ **Post date:** [November 2, 2021, 10:25am UTC](https://forum.dynamobim.com/t/doesintersection-problem/69876/4 "2021-11-02T10:25:55Z")
Yes, now add the previous (list.map) and current (list.map) So you get the cumulative add on list ---
**Author:** ![Laura420](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/laura420/32/129127_2.png) [@Laura420](https://forum.dynamobim.com/u/Laura420)\ **Post date:** [November 2, 2021, 10:33am UTC](https://forum.dynamobim.com/t/doesintersection-problem/69876/5 "2021-11-02T10:33:40Z")
Sorry, I have a problem to understand the way of adding list, can you explain this more clearly? ---
**Author:** ![Laura420](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/laura420/32/129127_2.png) [@Laura420](https://forum.dynamobim.com/u/Laura420)\ **Post date:** [November 2, 2021, 10:40am UTC](https://forum.dynamobim.com/t/doesintersection-problem/69876/6 "2021-11-02T10:40:00Z")
I extend one edge and now it’s ok for surface 0 but surface 5 have the same problem with surface 3 and 6 ![obraz_2021-11-02_113958](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/5/f/5f8627013b4f39ce265cb7490eab398e6b322c01.png) ---
**Author:** ![honeyjain619](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/honeyjain619/32/121215_2.png) [@honeyjain619](https://forum.dynamobim.com/u/honeyjain619)\ **Post date:** [November 2, 2021, 10:41am UTC](https://forum.dynamobim.com/t/doesintersection-problem/69876/7 "2021-11-02T10:41:07Z")
![obraz_2021-11-02_005836](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/d/d/dd2d4ef3aa1f4a4b1160ddf77a01d71f71e02361.png) ---
**Author:** ![Laura420](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/laura420/32/129127_2.png) [@Laura420](https://forum.dynamobim.com/u/Laura420)\ **Post date:** [November 2, 2021, 10:45am UTC](https://forum.dynamobim.com/t/doesintersection-problem/69876/8 "2021-11-02T10:45:47Z")
![obraz_2021-11-02_114539](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/5/c/5c45b2c0b7c99c75c93d9c7afd40ae41cd60ea6f.png) Here surface 0 has also only one intersection with other surface ---
**Author:** ![Laura420](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/laura420/32/129127_2.png) [@Laura420](https://forum.dynamobim.com/u/Laura420)\ **Post date:** [November 2, 2021, 10:49am UTC](https://forum.dynamobim.com/t/doesintersection-problem/69876/9 "2021-11-02T10:49:19Z")
But it is interesting when i extend surface 0 and 5, then they have two intersection, I don’t understand why befor it not working ![obraz_2021-11-02_114929](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/a/0/a00670f46fa7199b58ca26647cbc504cc4af34fd.png) and when I back with previous geometry it look the same ![obraz_2021-11-02_115128](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/0/7/07c71a87490be78316d50cea2c8d21bd60e49eca.png) ---
**Author:** ![honeyjain619](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/honeyjain619/32/121215_2.png) [@honeyjain619](https://forum.dynamobim.com/u/honeyjain619)\ **Post date:** [November 2, 2021, 10:51am UTC](https://forum.dynamobim.com/t/doesintersection-problem/69876/10 "2021-11-02T10:51:33Z")
hahaha… 😛 those are input issues. ---
**Author:** ![Laura420](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/laura420/32/129127_2.png) [@Laura420](https://forum.dynamobim.com/u/Laura420)\ **Post date:** [November 2, 2021, 10:52am UTC](https://forum.dynamobim.com/t/doesintersection-problem/69876/11 "2021-11-02T10:52:02Z")
What do you mean? ---
**Author:** ![honeyjain619](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/honeyjain619/32/121215_2.png) [@honeyjain619](https://forum.dynamobim.com/u/honeyjain619)\ **Post date:** [November 2, 2021, 10:55am UTC](https://forum.dynamobim.com/t/doesintersection-problem/69876/12 "2021-11-02T10:55:46Z")
In input or on the surface (roof element) if you are adjusting some thing then only result will change. (like for surface 0 intersect with 1 elements and after change 2 elements) for knowing more i need to know more about the surface and other part of the script. But i think you got what you want, Now you are other issue with the inputs ---
**Author:** ![Laura420](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/laura420/32/129127_2.png) [@Laura420](https://forum.dynamobim.com/u/Laura420)\ **Post date:** [November 2, 2021, 12:23pm UTC](https://forum.dynamobim.com/t/doesintersection-problem/69876/13 "2021-11-02T12:23:56Z")
After simplify previous step of script it works, i don’t know what was the reason but now it is ok 😃 Thank you!