BUG: Clustering entities with point and label is broken (label not shown, updating label partial)

CesiumJS
1

Hello,

I recently upgraded Cesium from v1.26 (3rd Oct 2016) to the current v1.34 and have noticed our clustered Site entities (a point and a label) no longer show their label. If I disable dataSource.clustering.enabled, then the labels appear ok. If I disable dataSource.clustering.clusterLabels, then the labels appear but they do not disappear when the points are clustered. I notice the EntityCluster.clusterLabels/Points/Billboards options were added in October last year after v1.26 that we were previously using.

I have confirmed this in the current Cesium Sandbox by modifying the Clustering Example to create a CustomDataSource with clustering enabled and 3 entities with both a point and a label:

The example will zoom to the 3 Site entities that are missing labels. Disable clustering using checkbox widget to see the labels appear. If you uncomment dataSource.clustering.clusterLabels = false you will see the labels appear but they do not disappear with the rest of the clustered entity.

Also in this buggy example, if you uncomment the block at the end to modify the entity.label.text after creation that you can normally do, the label text will partially show - only new characters beyond the length of the original text or where there were spaces in the original text will show. Eg original text ‘foo bar’ updated to ‘1234567890’ will show ’ 4 890’ on screen ?!? The partial text does not disappear when the points are clustered though. :frowning:

Thanks,

Brendan

Screen Shot 2017-06-21 at 3.01.27 pm.png
Screen Shot 2017-06-21 at 3.01.27 pm.png704×508 628 KB

2

I would like to add that if you also have a billboard as part of the entity, then it gets clustered as though its separate to the point. I often use billboards for icons with a point as the background circle but have to set the billboard eyeOffset to e.g. new Cartesian3(0, 0, -5) to bring it in front due to z testing.

On a separate note, I noticed in the main render method seems to render labels before points which causes label to be rendered with anti aliasing against the globe and then points are rendered after so labels have terrible artefact and are not very clear.

I believe it would be better to use HTML divs for markers - I thought there was mention of this recently in the Cesium blog but I cannot find reference to it anymore.

3

I’m posting this to a similar open issue on your GitHub Cesium project: https://github.com/AnalyticalGraphicsInc/cesium/issues/4919

4

Hi Brendan,

Thanks for reporting this bug! It’s been noted and marked as priority for our dev team – we’ll let you know when we get a chance to work on it.

Thanks,

  • Rachel