Polyline switching in and out

CesiumJS
1

1. A concise explanation of the problem you’re experiencing.

A path is drawn across the globe using a polyline. However, the polyline sometimes disappears depending on zoom / rotation.

I’m guessing this has something to do with culling objects past the horizon or similar filter.

2. A minimal code example. If you’ve found a bug, this helps us reproduce and repair it.

Try zooming into Australia:

https://dev.globaltimoto.com

In this simplified test if you zoom into either end of the polyline then tilt then rotate the line will also dissaper as it rotate along the bottom of the screen.

http://www.globaltimoto.com/cesium/Apps/test.html

3. Context. Why do you need to do this? We might know a better way to accomplish your goal.

Polylines describing a path to travel should always render. Is there a way to achieve this ?

4. The Cesium version you’re using, your operating system and browser.

This is present in v1.48 and v1.49

2

I have since discovered that it is possible to cull a polyline as short as:

var pathBoundaries = [0,0, -15,0]

The larger the path boundary the easier it is to cull the path from the scene. The attached video shows how easy it is to reproduce.

polyline-cull.mp4 (4.96 MB)

3

Is there a way to stop a polyline from being culled ?

Or is there another method I should be using ?

4

I found that the cause of this issue is related to

scene3DOnly: true

``

I’ve described the way to reproduce the bug here:

https://github.com/AnalyticalGraphicsInc/cesium/issues/7043

5

Thanks for the thorough analysis and for opening up the GitHub issue Tim!