# Interpolating a polyline?

**URL:** <https://community.cesium.com/t/interpolating-a-polyline/11865>\
**Category:** CesiumJS\
**Created:** [December 25, 2020, 11:46pm UTC](https://community.cesium.com/t/interpolating-a-polyline/11865 "2020-12-25T23:46:26Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Yordan\_Yanakiev1](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/yordan_yanakiev1/32/2128_2.png) [@Yordan\_Yanakiev1](https://community.cesium.com/u/Yordan_Yanakiev1)\
**Post date:** [December 25, 2020, 11:46pm UTC](https://community.cesium.com/t/interpolating-a-polyline/11865/1 "2020-12-25T23:46:26Z")

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Hello dear devs.  
I have polyline objects defined as :  
polyline:  
{  
classificationType: Cesium.ClassificationType.TERRAIN,  
positions: Cesium.Cartesian3.fromDegreesArray( points ),  
width: 6,  
material: new Cesium.PolylineOutlineMaterialProperty(  
{  
color: color.withAlpha( 0.6 ),  
outlineWidth: 1,  
outlineColor: Cesium.Color.BLACK.withAlpha( 0.40 )  
} ),  
clampToGround: true  
}

and I would love if this can be interpolated somehow.

- is there a way to do so ?

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**Author:** ![hannah](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/hannah/32/4509_2.png) [@hannah](https://community.cesium.com/u/hannah)\
**Post date:** [January 4, 2021, 4:53pm UTC](https://community.cesium.com/t/interpolating-a-polyline/11865/2 "2021-01-04T16:53:03Z")

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@Yordan_Yanakiev1 It depends what you’re trying to accomplish. The Cesium library does have a few interpolation algorithms: [HermitePolynomialApproximation - Cesium Documentation](https://cesium.com/docs/cesiumjs-ref-doc/HermitePolynomialApproximation.html)[LagrangePolynomialApproximation - Cesium Documentation](https://cesium.com/docs/cesiumjs-ref-doc/LagrangePolynomialApproximation.html)

There isn’t a way to automatically apply these to your polyline via the Entity API, but you can use those algorithms to pre-compute your positions array. The Entity API does however have built-in support interpolation for `position` property used to draw a `path`. See [Cesium Sandcastle](https://sandcastle.cesium.com/?src=Interpolation.html&label=All)

Cheers,

Hannah  
Cesium Staff

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<div class="post-metadata">

**Author:** ![Yordan\_Yanakiev1](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/yordan_yanakiev1/32/2128_2.png) [@Yordan\_Yanakiev1](https://community.cesium.com/u/Yordan_Yanakiev1)\
**Post date:** [January 5, 2021, 12:05pm UTC](https://community.cesium.com/t/interpolating-a-polyline/11865/3 "2021-01-05T12:05:02Z")

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Hey Hannah !  
Thank You for Your reply.  
Well… I just have a polylines which is updated each couple of seconds, and I would like to have interpolation on them. to be more… smooth in some way.

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**Author:** ![harshad\_P\_P](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/harshad_p_p/32/11848_2.png) [@harshad\_P\_P](https://community.cesium.com/u/harshad_P_P)\
**Post date:** [January 18, 2023, 7:04am UTC](https://community.cesium.com/t/interpolating-a-polyline/11865/4 "2023-01-18T07:04:23Z")

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Hey @Yordan_Yanakiev1 have you got any solution for this?  
can you please share your thoughts on this

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<div class="post-metadata">

**Author:** ![harshad\_P\_P](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/harshad_p_p/32/11848_2.png) [@harshad\_P\_P](https://community.cesium.com/u/harshad_P_P)\
**Post date:** [April 12, 2023, 5:33am UTC](https://community.cesium.com/t/interpolating-a-polyline/11865/5 "2023-04-12T05:33:42Z")

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@hannah hey hannah, is that possible to apply any of these interpolation algorithm to interpolate a polyline?