dear cesium team, i added a kml datasource that containes only polylines, when i zoom in to the line it disappears suddenly. i removed the kml then i added a polyline as entity, same result, the polyline disappears on zooming in. on zooming out it appears again. after many trials, i noticed that…

Welcome to the Cesium community! It sounds like you may need to clamp the line to the ground. See the discussion in this thread: Label is gone when it is zoomed out

Thank you very much. i have put this property already. clampToGround : true, and the lines are clamping, but the problem is not solved.

something weird is happening here, the problem is with the tessellate tag, i created a kml with 2 lines, both clampToGround is true. first line is tessellate true, and second one is tessellate false. when i add the kml from viewer,.datasources.add(datasourceKML) the second line appears immedia…

this video will show you what is happening with me. 1 kml contains 2 lines with tessellate true and clampedToGround true.[lines2]

That does look like it could be a bug. Can you put together a code example for us to reproduce this? You can share your KML by uploading it to your Cesium ion account and using it in a code example.

line.kml (1.3 KB) i attached the kml file. and this is the code : var kmlds = KmlDataSource.load(‘PathToKML’,{ camera : viewer.scene.camera, canvas: viewer.scene.canvas, clampToGround: true}); viewer.dataSources.add(kmlds);

I’m not able to reproduce this. <a href="https://sandcastle.cesium.com/#c=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">Here’s my Sandcastle . You can modify this to move the camera to the spot where this issue happens if you can reproduce it. Use the “get camera” button and copy the output into the viewer.camera.flyTo line.

i found in cesium issues on github an issue considering polylines clam to ground with kml. and you answered in that issue that the problem was with the tessellate tag. also in that issue you gave a link to a sandcastle. i entered the link and i have put my kml instead of yours. but i kept the same …

dear @omar , still didn’t found any solution?

Lines disappears on zooming in

CesiumJS

omar August 19, 2020, 1:00pm 4

Can you reproduce the issue in a Sandcastle? See: How to share custom Sandcastle examples.

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Lines disappears on zooming in

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