# Array and Rotation along a curvev

**URL:** <https://forum.dynamobim.com/t/array-and-rotation-along-a-curvev/35250>\
**Category:** Revit\
**Tags:** dynamo\
**Created:** [April 26, 2019, 10:45am UTC](https://forum.dynamobim.com/t/array-and-rotation-along-a-curvev/35250 "2019-04-26T10:45:28Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![edward1234](https://avatars.discourse-cdn.com/v4/letter/e/8c91f0/32.png) [@edward1234](https://forum.dynamobim.com/u/edward1234)\
**Post date:** [April 26, 2019, 10:45am UTC](https://forum.dynamobim.com/t/array-and-rotation-along-a-curvev/35250/1 "2019-04-26T10:45:28Z")

</div>

Hello,

I am trying to create a graph that will array a revit family along a curve and rotate it so that the element is always facing towards the centre point of the curve.

So far I have created tangents along the line at the insertion points and rotated the elements by the degree between the tangent and x axis.

I think its do do with the y value of the tangent being +ve or -ve but I cant work it out.

Thanks in advance ![Array Script-ORIGINAL.dyn|attachment](https://cdck-file-uploads-us1.s3.dualstack.us-west-2.amazonaws.com/flex022/uploads/dynamobim/original/3X/1/e/1e9f51247516ec9f318ff6f3fcd38608f32f0c70.dyn) (32.9 KB)

---

<div class="post-metadata">

**Author:** ![saju\_autodesk](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/saju_autodesk/32/61838_2.png) [@saju\_autodesk](https://forum.dynamobim.com/u/saju_autodesk)\
**Post date:** [April 26, 2019, 10:50am UTC](https://forum.dynamobim.com/t/array-and-rotation-along-a-curvev/35250/2 "2019-04-26T10:50:32Z")

</div>

Hope this one helps

> [@Copy family instance to follow a curve](https://forum.dynamobim.com/t/copy-family-instance-to-follow-a-curve/28984/7):
>
> 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.

---

<div class="post-metadata">

**Author:** ![edward1234](https://avatars.discourse-cdn.com/v4/letter/e/8c91f0/32.png) [@edward1234](https://forum.dynamobim.com/u/edward1234)\
**Post date:** [April 26, 2019, 10:52am UTC](https://forum.dynamobim.com/t/array-and-rotation-along-a-curvev/35250/3 "2019-04-26T10:52:12Z")

</div>

I forgot to say the problem, it places it along the curve but it does not always rotate the familys properly.