# Shatter parameter (t) incorrect on first and last list items

**URL:** <https://discourse.mcneel.com/t/shatter-parameter-t-incorrect-on-first-and-last-list-items/116629>\
**Category:** Grasshopper\
**Tags:** windows, shatter\
**Created:** [January 20, 2021, 3:03am UTC](https://discourse.mcneel.com/t/shatter-parameter-t-incorrect-on-first-and-last-list-items/116629 "2021-01-20T03:03:36Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![ken.marold](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/ken.marold/32/757475_2.png) [@ken.marold](https://discourse.mcneel.com/u/ken.marold)\
**Post date:** [January 20, 2021, 3:03am UTC](https://discourse.mcneel.com/t/shatter-parameter-t-incorrect-on-first-and-last-list-items/116629/1 "2021-01-20T03:03:36Z")

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Totally stumped on this issue. I’m shattering a collection of curves (getting my params using CCX). Almost everything works fine…except, I believe for the first item in the first and last branch. The shatter point param value is incorrect, it’s breaking only those two curves in the worng place. If you look at the results of the definition you’ll see that two curves are not shattering at the actual insection points. Super appreciate any help with this. Thank you!

[shatter\_t\_skewed.gh](https://discourse.mcneel.com/uploads/short-url/b3oTSecYxv6me4XGB8RrqPumXYK.gh) (56.3 KB)

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**Author:** ![HS\_Kim](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/hs_kim/32/473975_2.png) [@HS\_Kim](https://discourse.mcneel.com/u/HS_Kim)\
**Post date:** [January 20, 2021, 5:01am UTC](https://discourse.mcneel.com/t/shatter-parameter-t-incorrect-on-first-and-last-list-items/116629/2 "2021-01-20T05:01:19Z")

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Have no idea why… Maybe some sort of tolerance issue?  
Anyway, here is a workaround for you.

 ![Canvas at 13;58;01](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/d/2/6/d2626f816bcc202b817bac8027b2d1502e66a5bb.png)  
[shatter\_t\_skewed\_re.gh](https://discourse.mcneel.com/uploads/short-url/mENrVg29BFpujK15UFzsCnKr0e1.gh) (52.9 KB)