GeoJsonDataSource.clampToGround polygons not working on Samsung S7, Android, Chrome

CesiumJS
1

I am still holding out some hope for a 3D avalanche forecast map that will work on mobile devices in the next year, or two…?

My development website successfully displays polygons clampedToGround on 3D terrain on a Windows desktop running 64bit Chrome (56.0.2924.87), using WebGL 1.0 with the EXT_frag_depth supported.

http://lftgly.com/wordpress/?page_id=253

I’ve upgraded to a Samsung S7 Galaxy.

The same webpage, running in Chrome (50.0.2661.89) on Android (6.0.1) displays the polygons only in 2D, not in 3D.

I expected the latest Samsung hardware would support Cesium’s polygons clampToGround feature in 3D.

webglreport.com shows this browser supports WebGL 1.0, (and this browser does not WebGL 2), however, EXT_frag_depth is not listed under supported extensions.

I tried two approaches:

  1. chrome://flags/#enable-webgl-draft-extensions to ENABLE WebGL Draft Extensions; then relaunch Chrome;

webglreport.com shows this browser supports WebGL 1.0, (and this browser does not WebGL 2), however, EXT_frag_depth is still not listed under supported extensions.

and of course, this still results in polygons only displaying in 2D mode;

  1. chrome://flags, Rest all to defaults; then relaunch Chrome;

chrome://flags/#enable-unsafe-es3-apis to ENABLE the WebGL 2.0 Protoype; then relaunch Chrome;

webglreport.com shows this browser supports (WebGL 1.0, and) WebGL 2.0 (OpenGL ES GLSL ES 3.0 Chromium),

however, this still results in polygons only displaying in 2D mode;

There is a lack of information available to troubleshoot this, though I have a few theories.

Is it premature to expect Cersium to run in Chrome on WebGL 2.0 Protoype?

What becomes of EXT_frag_depth in WebGL 2.0 Core? What is it called?

chrome://gpu on the S7 reports a Qualcomm GL_vendor, and among 14 “Problems detected”, includes “disable depth textures on Android with Qualcomm GPUs”, which sounds relevant.

Best regards,

Jon “Left Gully” Hall…

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PS. running Cesium v1.29

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Hello Jon,

We actually just made a fix in 1.31 that allows polygons to render clamped to terrain without relying on the EXT_frag_depth extension. Try upgrading to that version and let me know if that works for you.

Best,

Hannah

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Excellent, I started to look up the changes, but digressed…

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Hannah-
I updated my development server from 1.29 to 1.31, and began to test.

The GeoJSON polygons clamped to ground now appear to work great in 3D on my Samsung S4 and S7 devices, that previously would not work. I was ecstatic, until I tested in 2D.

I then noted the “disappearing” polygons in 2D, apparently the same bug already reported, and hopefully fixed, in https://github.com/AnalyticalGraphicsInc/cesium/issues/5075

Please note that the “disappearing” polygons were rendering in 2D, but about a mile southeast of their correct geolocation.

I will wait for 1.32 before further 2D testing.

Best regards-

-Jon “left gully” Hall

PS. One last request: consider releasing v1.32 the day before or after April Fools Day, I am superstitious about software “bug” fixes promised for release on April 1st. Probably just a case of ESRI-phobia acquired from years developing on the ArcGIS platform.

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Great! Glad to hear ground clamping is working on your mobile devices! Hopefully you’ll be all set after 1.32 is released.
1.32 will be released on April 3rd because the 1st falls on a weekend =)

-Hannah