# Clamping to ground PointPrimitiveCollection

**URL:** <https://community.cesium.com/t/clamping-to-ground-pointprimitivecollection/9192>\
**Category:** CesiumJS\
**Created:** [March 26, 2020, 2:49pm UTC](https://community.cesium.com/t/clamping-to-ground-pointprimitivecollection/9192 "2020-03-26T14:49:49Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![11160](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/11160/32/2084_2.png) [@11160](https://community.cesium.com/u/11160)\
**Post date:** [March 26, 2020, 2:49pm UTC](https://community.cesium.com/t/clamping-to-ground-pointprimitivecollection/9192/1 "2020-03-26T14:49:49Z")

</div>

Dear Cesium users and team!

How to clamp to ground PointPrimitiveCollection?

I have tried this code in sandcastle, but it is not working ☹

var viewer = new Cesium.Viewer(‘cesiumContainer’, {

terrainProvider: Cesium.createWorldTerrain()

});

viewer.scene.globe.depthTestAgainstTerrain = true;

var points = viewer.scene.primitives.add(new Cesium.PointPrimitiveCollection({

heightReference : Cesium.HeightReference.CLAMP\_TO\_GROUND

}));

for (var longitude = -180; longitude \< 180; longitude++) {

var color = Cesium.Color.PINK;

if ((longitude % 2) === 0) {

color = Cesium.Color.CYAN;

}

for (var latitude = -90; latitude \< 90; latitude++) {

points.add({

position : Cesium.Cartesian3.fromDegrees(longitude, latitude),

color : color,

heightReference : Cesium.HeightReference.RELATIVE\_TO\_GROUND

});

}

}

Any help would be greatly appreciated.

Sincerely,

Ru