display artefacts with polygons

[jau...@gmail.com]

When zooming really closer to a polygon entity, it disappears partially which is not expected.

Then, when zoomed out, it appears again fully.

Here is a screenshot which display the artefact:

It would be the following indeed:

I do not understand why it disappears, the polygon would be fully rendered anytime.

Code which reproduce the issue.

var viewer = new Cesium.Viewer('cesiumContainer');
var bluePolygon = viewer.entities.add({
    polygon : {
        hierarchy : {
            positions : Cesium.Cartesian3.fromDegreesArray([-99.0, 30.0,
                                                            -85.0, 30.0,
                                                            -85.0, 40.0,
                                                            -99.0, 40.0]),
        },
        material : Cesium.Color.BLUE.withAlpha(0.5),
        height : 0,
        outline : true // height is required for outline to display
    }
});
viewer.zoomTo(viewer.entities);

Cesium 1.61

Windows 10

Chrome 76 / Firefox 69

Could be reproduced with height > 0, with or without outline, with "recent" releases of cesium, browsers, etc.

I just would like to know if this is a "famous issue" which cannot be solved and if I can do something to workaround it.

Thank you to give me help.

[Omar Shehata]

This is a known issue with the logarithmic depth buffer. See: https://github.com/AnalyticalGraphicsInc/cesium/issues/6573

You can turn it off with:

viewer.scene.logarithmicDepthBuffer = false;

What kind of application are you working on?

[jau...@gmail.com]

Thanks Omar, it works perfectly !