What is the maximum altitude for polylines

Cesium ion
1

What is the maximum altitude polylines can have ?

I ask because if I make a polyline using an altitude typically over 100,000 Km (multiplying by 1000 for meters), the polyline and other polylines with much smaller altitudes do not show up. This is for showing some orbits around the Earth.

Best regards.

2

Hi. What viewer are you using to view the data?

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3

Cesium Ion.

4

Ok. So Cesium ion using CesiumJS internally.

Are you seeing this issue in Stories, the asset details preview, or somewhere else? Also can you provide an asset id of the asset that you expect to be able to view but cannot?

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5

I am a newbie, what is the “Stories” you mention ? I am using javascript to make polylines around the globe (basically orbits), this works in general, but when I make them the larger altitude (e.g. > 100,000 km * 1000 m, the polylines do not show up. Regarding the asset ID, you mean this: Cesium.IonImageryProvider.fromAssetId(3954) ?

6

Cesium Stories is a feature of Cesium ion. It lets you create 3D geospatial presentations.

I’m a bit confused since Cesium ion does not let you add javascript. Are you maybe using the sandcastle.cesium.com site that ion links to?

If you are using sandcastle, can you use the share feature to post a URL to the code you are having trouble with? If not, please let us know the URL of the page where you are viewing the data.

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7

Cesium Ion is shown on the map that is created in lower left when the globe is created via the call:

const viewer = new Cesium.Viewer(‘cesiumContainer’, options3D);

sorry, I am not sure how to reference it properly, maybe cesium.js.

I will try to make a repro on sandcastle. But, in general, how far should the polylines be able to be created ?

8

In theory 1.8 x 10308 based on the limits of the double precision floating point representation (IEEE 754). But in reality it is going to be less.

100,000,000 meters seems reasonable for double precision, but it is hard to say without knowing the specifics. For example, the GPU may only support single precision floating point. That is why the best way to troubleshoot this is to share a reproducible example with Sandcastle.

That is part of the credits. It is just indicating that the data shown came from Cesium ion. It sounds like you are using CesiumJS.

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