How to Check if a Point is Inside a Polygon in Cesium (Including 180° Meridian and Poles)

[Keei]

In Cesium, given a set of latitude and longitude points that form a polygon with entity appearances as shown in the figure, if I specify a point P, how can I determine whether this point lies inside the polygon? Does this method remain applicable when the polygon crosses the 180-degree longitude line or contains polar points?

Cesium Sandcastle

[Luke_McKinstry]

Hi @Keei ,

Thanks for your post.

TurfJS has a function for this.

Polygon Contains Cartographic

There isn’t a built-in way to do this as far as I’m aware, but detecting if a point is inside a polygon is a common graphics operation (you’ll find a few different algorithms if you google that). You could use a library like TurfJS and give it the coordinates of your polygons/points: https://turfjs.org/docs/#pointsWithinPolygon What kind of application are you working on?

Would that work for you? Please let us know if not and I would be happy to try and help more.

Thanks,
Luke

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