# Sun termination line

**URL:** <https://community.cesium.com/t/sun-termination-line/3956>\
**Category:** CesiumJS\
**Created:** [April 5, 2016, 9:01pm UTC](https://community.cesium.com/t/sun-termination-line/3956 "2016-04-05T21:01:53Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Josiah\_Allen](https://avatars.discourse-cdn.com/v4/letter/j/ebca7d/32.png) [@Josiah\_Allen](https://community.cesium.com/u/Josiah_Allen)\
**Post date:** [April 5, 2016, 9:01pm UTC](https://community.cesium.com/t/sun-termination-line/3956/1 "2016-04-05T21:01:53Z")

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The day/night lighting is very nice, but it would also be nice to show where the sunlight is simply by drawing a sun termination line, which is the border between day and night, instead of relying on the shadow to demarcate that border.

Or alternatively, being able to obtain the point on the globe that represents the center of the daylight.

Any thoughts or is this a feature request? Or a 'Do your own math!' problem...

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**Author:** ![Jason\_D](https://avatars.discourse-cdn.com/v4/letter/j/9f8e36/32.png) [@Jason\_D](https://community.cesium.com/u/Jason_D)\
**Post date:** [July 14, 2016, 4:32pm UTC](https://community.cesium.com/t/sun-termination-line/3956/2 "2016-07-14T16:32:14Z")

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I’ve got a similar problem. The globe only enables lighting in the 3D view. Is there a way to get the lighting in the 2D view? Or can someone point me to where the code calculates the sunlighting in 3D, so I can draw sunlight/penumbra/umbra transition lines in non-3D views?

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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:** [July 14, 2016, 9:29pm UTC](https://community.cesium.com/t/sun-termination-line/3956/3 "2016-07-14T21:29:25Z")

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Hello,

I don’t think we currently have the ability to draw the sun termination line. I wrote up an issue here: [https://github.com/AnalyticalGraphicsInc/cesium/issues/4123](https://github.com/AnalyticalGraphicsInc/cesium/issues/4123)

I think that would be something useful for other users. Would either of you be interested in implementing it? If so, you can post on that GitHub issue asking for tips for how to calculate it.

Also see our contributors documentation and the build guide for instructions on checking out the code base and building it: [https://github.com/AnalyticalGraphicsInc/cesium/tree/master/Documentation/Contributors/BuildGuide](https://github.com/AnalyticalGraphicsInc/cesium/tree/master/Documentation/Contributors/BuildGuide)

Regarding lighting in 2D- that’s a bug. Thanks for bringing that up! I wrote a separate issue here for us to look into it, so hopefully it’ll be fixed soon: [https://github.com/AnalyticalGraphicsInc/cesium/issues/4122](https://github.com/AnalyticalGraphicsInc/cesium/issues/4122)

Best,

Hannah