Rendering glitches with flat ground-level graphics

[joneschrisg]

Hello, I feel that this is probably a duplicate but I wasn't able to find one. I see this on a mid-2014 Macbook Pro with NVIDIA GPU, running OS X 10.12.3.

Steps to reproduce:

0. Load http://cesiumjs.org/Cesium/Apps/Sandcastle/index.html?src=Polygon.html&label=Showcases in Firefox 51 or Chrome 56
1. Zoom in and out from ground level to at least the height of screenshot below

Note the red and blue polygons are only partially rendered. This seems to happen with terrain both off and on. I've also seen this same glitch with EllipseGraphics. I think is a regression from within the last month or so.

A workaround is to set the graphics height or extrudedHeight to 1.

[hpinkos]

Thanks @joneschrisg. I can't reproduce this on my windows machine, but we did fix a problem like this in the 1.29 release so I'm surprised you're seeing this .

Does anyone else with a Mac have this problem? @pjcozzi? @rahwang?

[pjcozzi]

I don't have this issue on Mac, but I agree it looks like the issue fixed in 1.29. See #4161

[joneschrisg]

Thanks for taking a look. Just to be 100% clear, I'm seeing this in 1.31. Updated screenshot is below.

[pjcozzi]

Hmm. Do you know for sure if it using the NVIDIA GPU or if it is running the integrated Intel?

[joneschrisg]

Sorry, I forgot to mention that too: I disabled automatic graphics switching when testing. (Even so, I didn't rigorously verify that the NVIDIA card was being used --- can do that if it'd help --- but I'm pretty sure it's been on.)

[joneschrisg]

Same symptom in Firefox 52 / Chrome 57.