GroundPrimitive rendering artifacts

[hpinkos]

Reported on the forum: https://groups.google.com/forum/?hl=en#!topic/cesium-dev/6qt-wb-SohY

This might be either mac or AMD specific. I wasn't able to reproduce this on my machine, but this user saw it on a Macbook Pro with an AMD GPU. It occurs when zooming in and viewing the polygon from certain angles. See the forum post for more details.

var viewer = new Cesium.Viewer('cesiumContainer');

var cesiumTerrainProviderMeshes = new Cesium.CesiumTerrainProvider({
    url : '//assets.agi.com/stk-terrain/world',
    requestWaterMask : true,
    requestVertexNormals : true
});
viewer.terrainProvider = cesiumTerrainProviderMeshes;

var pos = [-106.70223205,40.50751048,3108,-106.70231189,40.50719517,3100,-106.7023843,40.50697001,3094,-106.70243232,40.50681935,3090,-106.70250271,40.5066019,3083,-106.70259377,40.50619344,3073,-106.70263983,40.50604864,3069,-106.70268295,40.50579201,3062,-106.70271371,40.50564398,3057,-106.70273965,40.50557274,3053,-106.70276796,40.50531077,3045,-106.70279042,40.50523906,3044,-106.70281277,40.50516771,3043,-106.70285192,40.50504112,3040,-106.70285105,40.50498227,3039,-106.70286683,40.50486993,3038,-106.70288338,40.5047512,3037,-106.70290059,40.50469215,3036,-106.70291193,40.50465355,3036,-106.70292889,40.5045959,3036,-106.70296262,40.50448086,3035,-106.70301364,40.50430164,3035,-106.70304165,40.50420326,3035,-106.70305836,40.50414445,3035,-106.70306945,40.50410539,3035,-106.70309699,40.50400864,3035,-106.703119,40.50393048,3035,-106.70311333,40.50382028,3035,-106.70311326,40.50375577,3035,-106.70310217,40.50366658,3036,-106.70309663,40.5035588,3036,-106.7031076,40.50351989,3036,-106.70310223,40.50347508,3037,-106.70311321,40.50343588,3037,-106.70312416,40.50339683,3037,-106.70314046,40.50333886,3038,-106.70317261,40.50328907,3037,-106.70318312,40.50325271,3037,-106.70323643,40.50319025,3037,-106.70326295,40.50315917,3037,-106.70330982,40.50305671,3037,-106.70333013,40.50298569,3037,-106.70334527,40.50293273,3037,-106.70339025,40.50277541,3037,-106.70340503,40.50272411,3037,-106.70343897,40.50260833,3037,-106.7034534,40.50255908,3037,-106.70347202,40.50249932,3036,-106.70348591,40.50245481,3035,-106.70350443,40.50239484,3034,-106.70351826,40.50235006,3033,-106.7035411,40.50227685,3032,-106.70355447,40.50223604,3031,-106.70349261,40.50221506,3031,-106.70309123,40.50207977,3034,-106.70200464,40.50176103,3036,-106.70087057,40.50172853,3035,-106.700331,40.5018247,3033,-106.69873514,40.50176053,3037,-106.69851119,40.50169164,3038,-106.69836038,40.50152504,3039,-106.69807085,40.50141102,3040,-106.69774118,40.50130369,3041,-106.69750227,40.50120541,3044,-106.69678538,40.50114025,3043,-106.69638718,40.50110116,3041,-106.69560964,40.50088376,3042,-106.69536529,40.50081604,3042,-106.69500127,40.50072198,3040,-106.69484808,40.50068738,3039,-106.69467942,40.50064713,3038,-106.69449011,40.50115032,3036,-106.69434659,40.50147135,3035,-106.6938443,40.50243353,3041,-106.69350654,40.50297144,3051,-106.6929781,40.50382496,3085,-106.69278407,40.50409533,3089,-106.69279539,40.50429847,3090,-106.69274412,40.50472061,3093,-106.69234961,40.50559242,3091,-106.69139427,40.50701375,3079,-106.69111443,40.50740422,3078,-106.69089001,40.50771678,3076,-106.69107519,40.50775148,3077,-106.69135232,40.50780339,3079,-106.69340584,40.50795246,3101,-106.69534761,40.50801909,3124,-106.69626365,40.50793214,3138,-106.69712806,40.50785158,3147,-106.69775128,40.5078214,3146,-106.69790381,40.50783061,3147,-106.6981772,40.50791936,3148,-106.69891842,40.50822559,3149,-106.69924123,40.50836704,3148,-106.6999645,40.50863474,3144,-106.700285,40.50866932,3141,-106.70037259,40.50867131,3141,-106.70042119,40.50865747,3141,-106.70074046,40.50862013,3139,-106.70090489,40.50865367,3137,-106.70128863,40.50868389,3135,-106.70141291,40.50870639,3133,-106.70162049,40.50874742,3130,-106.70166649,40.50874076,3130,-106.70173136,40.50874534,3128,-106.70179559,40.50875389,3127,-106.7018538,40.50877897,3127,-106.70191239,40.50880195,3126,-106.70199749,40.50880949,3125,-106.70206303,40.5088092,3124,-106.70207731,40.50875908,3124,-106.70208575,40.50865554,3123,-106.70208719,40.50857644,3122,-106.70206234,40.50851386,3121,-106.70204609,40.50834978,3120,-106.70202152,40.50828782,3119,-106.70201622,40.50823352,3119,-106.7020374,40.50816088,3118,-106.70203956,40.50808012,3117,-106.70206062,40.50800797,3117,-106.70207459,40.50796008,3116,-106.70208849,40.50791261,3116,-106.70210864,40.50784577,3115,-106.70213527,40.50775779,3113,-106.70214837,40.50771513,3112,-106.70216142,40.50767258,3112,-106.70217444,40.50763016,3111,-106.7021939,40.50756674,3109,-106.70220682,40.50752462,3109];

var myGeom = new Cesium.GeometryInstance({
    geometry: new Cesium.PolygonGeometry({
        polygonHierarchy: {
            positions: Cesium.Cartesian3.fromDegreesArrayHeights(pos)
        }
    }),
    attributes: {
        color: Cesium.ColorGeometryInstanceAttribute.fromColor(new Cesium.Color(1.0, 0.0, 0.0, 0.4))
    }
});

viewer.scene.groundPrimitives.add(new Cesium.GroundPrimitive({
    geometryInstance: myGeom
}));

viewer.scene.camera.setView({destination: Cesium.Cartesian3.fromDegrees(-106.7022, 40.5075, 10000)});

[pjcozzi]

This is may be a bug in the AMD driver. This works on my MacBook Pro with NVIDIA. Are they running the latest version of OS X?

[hpinkos]

He said he's running OSX 10.10.5 (Yosemite)

[hpinkos]

Also reported by this user: https://groups.google.com/forum/?hl=en#!topic/cesium-dev/iBuJiV2-EkE
Running OSX 10.11 and an AMD graphics card.

[slightHYP]

I confirm the bug:

Mac Pro
OSX Yosemite 10.10.5
2 x 3 GHz Quad-Core Intel Xeon
12 GB RAM
ATI Radeon HD 5770

I will try to update the OS.

[chriseyhorn]

I am also getting this error on my Mac running 10.11 with AMD graphics card. Same behavior across Chrome and Safari. Everything looks fine until I get to a specific zoom level and then it looks like the other screen shots above.

[slightHYP]

Hi everyone, any news about this issue...Probably is not related directly with CesiumJS core, more with the ATI drivers... but, anyhow, do you have any suggestion, workaround or fix?

Mac Pro
OSX El Capitan 10.11.5
2 x 3 GHz Quad-Core Intel Xeon
12 GB RAM
ATI Radeon HD 5770

Thank you,
Michele

[pjcozzi]

@slightGT no update yet, but I suspect we will need to add a workaround in Cesium since Apple does not update drivers often.

We are currently improving polygons on terrain for 3D Tiles (#3241) so there's a chance we will also fix this in the process.

[slightHYP]

@pjcozzi Thanks, I will follow the improvements in the 3DTiles branch.

[douglasbodkin]

I am also experiencing this issue on a 2015 MacBook Pro (AMD Radeon R9 M370X 2GB; OS X El Capitan 10.11.5) and a 2016 MacBook Pro (AMD Radeon Pro 455 2GB; macOS Sierra 10.12.4). The first screenshot shows the polygon while zoomed out and the second displays the issue while zoomed in:

[pjcozzi]

@douglasbodkin when you visit http://webglreport.com/, does it report "EXT_frag_depth" at the bottom?

[douglasbodkin]

@pjcozzi Yes, it lists "EXT_frag_depth" at the bottom. Here is the full report:

[pjcozzi]

Thanks @douglasbodkin, I was afraid that would be the answer! 😄

[mramato]

I can reproduce this locally as well (on the old Mac we have, which is also an AMD card).

[pcmehlitz]

it seems this is still pertinent on current Apple hardware (M1/M2) - see https://community.cesium.com/t/macos-driver-bug-for-small-clamp-to-ground-polygons/24277