# Polygon fill artifact

**URL:** <https://community.cesium.com/t/polygon-fill-artifact/2052>\
**Category:** CesiumJS\
**Created:** [February 23, 2015, 5:33pm UTC](https://community.cesium.com/t/polygon-fill-artifact/2052 "2015-02-23T17:33:56Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Robert\_Vorthman](https://avatars.discourse-cdn.com/v4/letter/r/46a35a/32.png) [@Robert\_Vorthman](https://community.cesium.com/u/Robert_Vorthman)\
**Post date:** [February 23, 2015, 5:33pm UTC](https://community.cesium.com/t/polygon-fill-artifact/2052/1 "2015-02-23T17:33:56Z")

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I’m new to Cesium so I apologize if this has already been discussed. I’ve noticed a polygon display issue that only affects 2D mode, not 3D or Columbus. If you view the [Sandcastle GeoJSON and TopoJSON example](http://cesiumjs.org/Cesium/Apps/Sandcastle/index.html?src=GeoJSON%20and%20TopoJSON.html&label=Tutorials) in 2D mode, there is a jagged edge that runs through Longitude -90 and what appears to be a shading affect applied to the polygon’s fill. This is apparent with both default and basic polygon styling, but is not present with custom styling.

[![](https://lh4.googleusercontent.com/-0sVjSd-nWDk/VOtjYu9uMuI/AAAAAAAAz3o/54hqOH5dg7s/s400/Screen%2BShot%2B2015-02-23%2Bat%2B12.18.03%2BPM.png)](https://lh4.googleusercontent.com/-0sVjSd-nWDk/VOtjYu9uMuI/AAAAAAAAz3o/54hqOH5dg7s/s1600/Screen%2BShot%2B2015-02-23%2Bat%2B12.18.03%2BPM.png)

I’m using Cesium to create a world map from TopoJSON for all country borders, and I’ve noticed the same issue occurs on the opposite side of the world, at Longitude 90.

[![](https://lh3.googleusercontent.com/-z7YdrrenwTg/VOtkLcnamwI/AAAAAAAAz34/PfMXnnfr95k/s400/Screen%2BShot%2B2015-02-23%2Bat%2B12.31.34%2BPM.png)](https://lh3.googleusercontent.com/-z7YdrrenwTg/VOtkLcnamwI/AAAAAAAAz34/PfMXnnfr95k/s1600/Screen%2BShot%2B2015-02-23%2Bat%2B12.31.34%2BPM.png)

[![](https://lh6.googleusercontent.com/--0Zxt75Pzxc/VOtkPSYJCoI/AAAAAAAAz4A/fHzRbTZUa68/s400/Screen%2BShot%2B2015-02-23%2Bat%2B12.31.49%2BPM.png)](https://lh6.googleusercontent.com/--0Zxt75Pzxc/VOtkPSYJCoI/AAAAAAAAz4A/fHzRbTZUa68/s1600/Screen%2BShot%2B2015-02-23%2Bat%2B12.31.49%2BPM.png)

Is there a workaround or can someone point me to the API documentation for disabling shading effects? Thanks.

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**Author:** ![patrick](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/patrick/32/2045_2.png) [@patrick](https://community.cesium.com/u/patrick)\
**Post date:** [February 25, 2015, 12:08am UTC](https://community.cesium.com/t/polygon-fill-artifact/2052/2 "2015-02-25T00:08:40Z")

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Hi Robert,

I suspect this is [#1825](https://github.com/AnalyticalGraphicsInc/cesium/issues/1825). As a workaround, you can _probably_ change [czm\_phong](https://github.com/AnalyticalGraphicsInc/cesium/blob/master/Source/Shaders/Builtin/Functions/phong.glsl#L29) to just

> vec4 czm\_phong(vec3 toEye, czm\_material material)

> {

> return vec4(material.diffuse, material.alpha);

> }

Then [rebuild](https://github.com/AnalyticalGraphicsInc/cesium/wiki/Contributor%27s-Guide) Cesium.

Patrick

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<div class="post-metadata">

**Author:** ![Robert\_Vorthman](https://avatars.discourse-cdn.com/v4/letter/r/46a35a/32.png) [@Robert\_Vorthman](https://community.cesium.com/u/Robert_Vorthman)\
**Post date:** [February 25, 2015, 1:50pm UTC](https://community.cesium.com/t/polygon-fill-artifact/2052/3 "2015-02-25T13:50:14Z")

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Thanks!

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<div class="post-metadata">

**Author:** ![Matt\_Amato](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/matt_amato/32/1993_2.png) [@Matt\_Amato](https://community.cesium.com/u/Matt_Amato)\
**Post date:** [February 27, 2015, 2:04am UTC](https://community.cesium.com/t/polygon-fill-artifact/2052/4 "2015-02-27T02:04:36Z")

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FYI, this has been fixed and will be in 1.7