Polyline geometry sometimes are drawn under the billboardCollection

Here’s an url of my demo:
mydemo
Based on PrimitiveCollection API, I have lower the polyline geometry to the bottom of the viewer.primitives and raised the billboardCollection to the top of the viewer.primitives.However, if I change the camera’s pitch to -90°(looking at the ground), i will see polyline geometry sometimes are drawn under the billboardCollection.


How can i avoid this problem and i don’t want to use the entity API, i need helps , plz!

Hi Noah,

Just a small clarification: you mean that the polyline is drawn over the spheres when you change the camera’s pitch to -90 degrees? And you would like the polyline to be drawn under the spheres at all times, is that correct?

yes,that’s what i need.And today i have tried using GroundPolylinePrimitive and GroundPolylineGeometry API to add polylines, the polyline is drawn over the spheres all time but it takes more time to draw polyline on globe and the fps is less than 15 when i move the map.Does it need more time to calculate?

Based on the documentation, the GroundPolylinePrimitive is draped over the terrain, which means there are additional computations needed to be made and which could explain the slower frame rate.

For the PrimitiveCollection, I am checking with our team to see if this is a bug. I will get back to you as soon as I hear back.

What kind of project are you working on?

Thank you dzung. Now I am working on a highway surveillance cameras information visualization project.The projects divides highways into more than 5,000 segments and it’s inefficient to use Entity API or GroundPrimitve API to draw them on map.Even sometimes the chrome would crash and my chrome verson is 84. In my testing, the best and most efficient way to draw more than 5.000 polyline on map is to use Primitive API with polylineGeometry.So i am looking forward to your reply! Thank you.