# Why the instance id picked with "Scene.pick" from primitive is not exact?

**URL:** <https://community.cesium.com/t/why-the-instance-id-picked-with-scene-pick-from-primitive-is-not-exact/24995>\
**Category:** CesiumJS\
**Created:** [June 26, 2023, 7:54am UTC](https://community.cesium.com/t/why-the-instance-id-picked-with-scene-pick-from-primitive-is-not-exact/24995 "2023-06-26T07:54:05Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![jingru1994](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/jingru1994/32/3458_2.png) [@jingru1994](https://community.cesium.com/u/jingru1994)\
**Post date:** [June 26, 2023, 7:54am UTC](https://community.cesium.com/t/why-the-instance-id-picked-with-scene-pick-from-primitive-is-not-exact/24995/1 "2023-06-26T07:54:05Z")

</div>

The official website tutorial has the following content about " Custom Geometry & Appearances".

> Instances are independently accessible after they are combined. Assign an `id` to an instance and use it to determine if the instance is picked with [`Scene.pick`](https://cesium.com/learn/cesiumjs/ref-doc/Scene.html#pick).

But I find that the pick.id is not the id of the geometry I clicked but the id of other geometries.  
For example, I clicked the left geometry but i obtained id of the right geometry in red box.  
 ![image](https://global.discourse-cdn.com/cesium/original/2X/5/510805c836623c98496b016230e8073a384e2402.png)  
Why does this happen and how can I get the exact id?  
Any feedback would be appreciated!