Glitchy display when rendering primitives

CesiumJS
1

Hello,

I'm trying to display a large set of 3d buildings but when I give the building exteriors transparency there are rendering issues. The buildings turn snowy. Not all of my team's computers see these issues, and in examining the GPUs and browser settings for WebGL we do not see any commonalities to work from.

I switched back to Alpha Blending using these flags:

      scene._translucentMRTSupport = false;
      scene._translucentMultipassSupport = false;

And it improved performance, somewhat. We ended up just turning off transparency for the time-being but now when we filter our buildings and re-color the entity polygon material, the solid exterior glitches, as well.

Does anyone know of any other method we can try to avoid this glitching?

best,
Vanessa

2

What OS/Browser/Graphics card are you using? Are you sure you have the latest drivers? Unfortunately these errors tend to be related Driver/OS related (most commonly being a problem on OS X with Intel cards) and isn’t something we can fix on the Cesium side of things.

3

I'm working with Vanessa. We've tested on a variety of macs. The 2010/2011 models don't seem to have a problem, but almost every newer machine does. We even bought several macs in the last couple weeks, all of them have the latest drivers. Across the board we are seeing "snow" when translucency is turned on -- except for our few older machines which seem to run fine -- even though they are intel machines with nvidia cards.

Even on a top of the line macbook pro, literally two days old, we are seeing this snow effect.

Bottom line: After testing on 8 different machines, we have come to the conclusion that transparency is not working on macs built on or after 2012.

Is anyone working on this problem? Is there some way we can pitch in?

Thanks,
Laura

4

Does translucency work in the Sandcastle examples like this one: http://cesiumjs.org/Cesium/Apps/Sandcastle/index.html?src=Geometry%20and%20Appearances.html&label=Showcases

Patrick

5

We've been working off this example to test translucency:

http://bagnell.github.io/cesium/Apps/Sandcastle/gallery/OIT.html

And we've found that Windows machines and older Macs usually have no issue seeing OIT or Alpha Blending translucency. Newer macs, especially Macs with Intel GPU, are prone to seeing fuzzy OIT rendered graphics. Have you seen this, as well?

best,
Vanessa

6

I have not seen this, but I could believe issues with OIT since it uses a few WebGL extensions. I expect this will improve as progress on WebGL 2 is made and the vendors do more testing. I would not expect issues with traditional alpha-blending.

Patrick

7

I’ll also add that OIT.html is a bad test case to use because it is based on an older version of Cesium and does not receive updates and fixes with each new release. Using the Sandcastle example is a better choice.