# Copy family instance to follow a curve

**URL:** <https://forum.dynamobim.com/t/copy-family-instance-to-follow-a-curve/28984>\
**Category:** Geometry\
**Created:** [November 27, 2018, 2:46pm UTC](https://forum.dynamobim.com/t/copy-family-instance-to-follow-a-curve/28984 "2018-11-27T14:46:51Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![pallen76](https://avatars.discourse-cdn.com/v4/letter/p/f475e1/32.png) [@pallen76](https://forum.dynamobim.com/u/pallen76)\
**Post date:** [November 27, 2018, 2:46pm UTC](https://forum.dynamobim.com/t/copy-family-instance-to-follow-a-curve/28984/1 "2018-11-27T14:46:51Z")

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Hi

Is there a simple way to place family instances following a curve, where the family orientates to the normal of the curve?

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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 27, 2018, 3:37pm UTC](https://forum.dynamobim.com/t/copy-family-instance-to-follow-a-curve/28984/2 "2018-11-27T15:37:26Z")

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Yes.

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**Author:** ![pallen76](https://avatars.discourse-cdn.com/v4/letter/p/f475e1/32.png) [@pallen76](https://forum.dynamobim.com/u/pallen76)\
**Post date:** [November 28, 2018, 9:18am UTC](https://forum.dynamobim.com/t/copy-family-instance-to-follow-a-curve/28984/3 "2018-11-28T09:18:19Z")

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Great, any chance you could elaborate?

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**Author:** ![pallen76](https://avatars.discourse-cdn.com/v4/letter/p/f475e1/32.png) [@pallen76](https://forum.dynamobim.com/u/pallen76)\
**Post date:** [November 28, 2018, 2:31pm UTC](https://forum.dynamobim.com/t/copy-family-instance-to-follow-a-curve/28984/5 "2018-11-28T14:31:58Z")

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Hi I’ve uploaded what I’ve done so far.

To elaborate, I’m looking to place family instances at points along a curve aligned to the normal of the curve. The dynamo script attached randomises the families placed and drives the length, but i can’t seem to figure out how to keep them orientated to the curve.

 ![image](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/a/6/a630fe1421701b6135966aeddb0dfdd6ca7816c2.png)

[divide curve.dyn](https://forum.dynamobim.com/uploads/short-url/5Lndqjs7Qpe9oZkuFSVhLtDWJhJ.dyn) (27.5 KB)

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<div class="post-metadata">

**Author:** ![pallen76](https://avatars.discourse-cdn.com/v4/letter/p/f475e1/32.png) [@pallen76](https://forum.dynamobim.com/u/pallen76)\
**Post date:** [November 28, 2018, 2:45pm UTC](https://forum.dynamobim.com/t/copy-family-instance-to-follow-a-curve/28984/6 "2018-11-28T14:45:56Z")

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As you can see the result works until the curve slopes up, then the families begin to twist off the curve normal.

 ![image](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/6/d/6d441b1f8be7c9711313cfff22102c83a7b777fc.png)

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**Author:** ![Joe.ashton](https://avatars.discourse-cdn.com/v4/letter/j/7993a0/32.png) [@Joe.ashton](https://forum.dynamobim.com/u/Joe.ashton)\
**Post date:** [November 29, 2018, 1:04pm UTC](https://forum.dynamobim.com/t/copy-family-instance-to-follow-a-curve/28984/7 "2018-11-29T13:04:31Z")

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Looks good, I can’t really work out the problem from the image you posted. might be worth trying to use “CurveTangentAtParameter”, like this example.

> [@Want to place the element along the curve](https://forum.dynamobim.com/t/want-to-place-the-element-along-the-curve/12721):
>
> Hi, I want to place the footings on the points with rotation as perpendicular to curve made my the points imported. Below I have created the dynamo script This is placing the elements as below I want like below Kindly help. Thanks Suresh C

 ![image](https://us1.discourse-cdn.com/flex022/uploads/dynamobim/original/3X/c/c/ccc5d1b3159b56a37a11e7db7d9629211c1b46db.png)