controlling culling of small circles on the globe

CesiumJS
1

I’m drawing small circles on the globe and would like them to remain visible when the camera is at high altitudes. What’s the best way to control when the circle is culled out? For example, if the code below is run in the sand castle, you’ll notice that you have to zoom in very far before the red circle will appear.

var viewer = new Cesium.Viewer(‘cesiumContainer’);

viewer.entities.add({
position: Cesium.Cartesian3.fromDegrees(-77, 39, 0),
ellipse: {
semiMajorAxis: 50000.0,
semiMinorAxis: 50000.0,
material: Cesium.Color.RED
}
});

``

Thanks,
Tim

2

Hello Tim,

I believe you’re running into this bug: https://github.com/AnalyticalGraphicsInc/cesium/issues/4161

Adding ‘height: 0’ to your ellipse should fix the problem for now.

Best,

Hannah

3

Thanks Hannah, that does fix the problem, but it doesn’t help if I want to use ground clamping (since I can’t specify height, in that case). Any idea what the priority of this bug is on the development roadmap?

Tim

4

Hi Tim,

The problem is related to the primitive type used for ground clamping. If you need ground clamping, you can try plugging in this proposed solution I submitted until we fix the problem in a better way: https://github.com/AnalyticalGraphicsInc/cesium/pull/4485

We have documentation for cloning and building the code base here: https://github.com/AnalyticalGraphicsInc/cesium/tree/master/Documentation/Contributors/BuildGuide

Sorry, I’m not sure exactly when we’ll have a chance to fix this bug. We have a lot of other things going on right now, but we do need to get this fixed as part of the 3D tiles work we’re doing.

-Hannah

5

Hi Tim,

I just wanted to let you know that the grand clamping but has been fixed and will be included in the 1.30 release available on February 1st. Let me know if you still see a problem!

Thanks,

Hannah

6

Hannah, thanks much for letting me know!

Tim