# Polycurve.ByPoints crashes Geometry.Intersect

**URL:** <https://forum.dynamobim.com/t/polycurve-bypoints-crashes-geometry-intersect/113081>\
**Category:** Civil 3D\
**Created:** [November 14, 2025, 2:53pm UTC](https://forum.dynamobim.com/t/polycurve-bypoints-crashes-geometry-intersect/113081 "2025-11-14T14:53:59Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![willyoungMF8K3](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/willyoungmf8k3/32/201327_2.png) [@willyoungMF8K3](https://forum.dynamobim.com/u/willyoungMF8K3)\
**Post date:** [November 14, 2025, 2:53pm UTC](https://forum.dynamobim.com/t/polycurve-bypoints-crashes-geometry-intersect/113081/1 "2025-11-14T14:53:59Z")

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Hi,

Does anyone have any idea why the Polycurve.ByPoints node would crash when plugged into Geometry.Intersect, but the Surface.ByPerimeterPoints node (using the same input points) doesn’t crash?

This is with Civil 3D 2026.

[foundation steps test.dyn](https://forum.dynamobim.com/uploads/short-url/tkJJuzSsQ2MJ9yXLcSlj16btO2E.dyn) (98.3 KB)

 ![image](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/c/1/c1d78206dec3553fbe5076ba5f3ef51270ddffaf.png)

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**Author:** ![jacob.small](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/jacob.small/32/161030_2.png) [@jacob.small](https://forum.dynamobim.com/u/jacob.small)\
**Post date:** [November 14, 2025, 3:10pm UTC](https://forum.dynamobim.com/t/polycurve-bypoints-crashes-geometry-intersect/113081/2 "2025-11-14T15:10:29Z")

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Can you show the data preview for whatever the Geometry input of the Geometry.Intersect node is, as well as the result of the Surface.ByPerimeterPoints and Polycurve.ByPoints (after you wire it in) nodes?

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<div class="post-metadata">

**Author:** ![willyoungMF8K3](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/willyoungmf8k3/32/201327_2.png) [@willyoungMF8K3](https://forum.dynamobim.com/u/willyoungMF8K3)\
**Post date:** [November 14, 2025, 3:21pm UTC](https://forum.dynamobim.com/t/polycurve-bypoints-crashes-geometry-intersect/113081/3 "2025-11-14T15:21:41Z")

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Thanks Jacob.

The geometry input is this stack of planes which are created at specified intervals:

 ![image](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/0/b/0b6f6f9809c10ebccda50b6dd6dcdc229355b757.png)

The surface and polycurve below are from a set of 4 points which have been generated from the mesh.project node.

 ![image](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/6/d/6d6f54e5f688108e2bc5b1893d61221d297cd0c0.png)

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<div class="post-metadata">

**Author:** ![willyoungMF8K3](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/willyoungmf8k3/32/201327_2.png) [@willyoungMF8K3](https://forum.dynamobim.com/u/willyoungMF8K3)\
**Post date:** [November 14, 2025, 3:35pm UTC](https://forum.dynamobim.com/t/polycurve-bypoints-crashes-geometry-intersect/113081/4 "2025-11-14T15:35:15Z")

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Ahhh.. it works when I flatten the list, sorry to waste your time.

 ![image](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/8/a/8ad94273ecfc1d1492c2c479676eb36371005ae0.png)

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<div class="post-metadata">

**Author:** ![jacob.small](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/jacob.small/32/161030_2.png) [@jacob.small](https://forum.dynamobim.com/u/jacob.small)\
**Post date:** [November 14, 2025, 3:55pm UTC](https://forum.dynamobim.com/t/polycurve-bypoints-crashes-geometry-intersect/113081/5 "2025-11-14T15:55:00Z")

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> [@willyoungMF8K3](#):
>
> sorry to waste your time.

No time wasted here! This does serve as a good example of the value of looking at the data structures. Reviewing such often is a good best practice.