black spots on globe?

We are seeing black spots on the globe sometimes when zooming panning. Has anyone seen this or are there any tips to diagnose it? I have tried to attach an image to this message.

We are Cesium 1.49, Windows 7 or 10, latest Chrome browser.

Thanks for letting us know. That definitely looks strange. I haven’t seen this before. Does it only happen with specific imagery providers? (If so, which ones?)

Do they disappear when moving? is it like a flicker or do they stay there as long as the camera isn’t moving? Are you able to recreate this in Sandcastle? (https://cesiumjs.org/Cesium/Build/Apps/Sandcastle/) you can click on the top right satellite image box to change the imagery.

If you can provide any more info to help us recreate it that’d help a lot!

They disappear when moving. They usually are on screen then disappear if you pan or zoom. I haven’t found it to be imagery provider specific. I will try to see if we can reproduce it in sandcastle. Thanks!

It seems to be from ArcGisImageServerTerrainProvider which we are still holding on to. It started causing problems for us somewhere between 1.42 and 1.48. We were not monitoring the group when you guys had asked if anyone was still using that ArcGisImageServerTerrainProvider.

Any tips on what to look at to address this would be appreciated. Thanks for your time.

I just found the discussion where it was removed:

You can read more about the reasons there. If you’re unable to switch to another terrain provider, you might be able to follow the steps Hannah describes in the comment I linked to put the removed class back, but it will involve making a custom build of CesiumJS.

Thanks Omar. I had seen that discussion and we have been keeping the class up to date by watching changes made to the other TerrainProvider classes. But somewhere between 1.42 and 1.48 we started seeing these black spots flicker on the globe from time to time when using the ArcGisImageServerTerrainProvider. I mean the terrain provider works for us, we’re just trying to figure out where the flickering black spots are coming from. The normally show up briefly while zooming or panning then go away when you stop moving the globe.

Attached is our up-to-date ArcGisImageServerTerrainProvider if anyone has the means to test the black dots issue :slight_smile:

ArcGisImageServerTerrainProvider.txt (11.9 KB)

It was something introduced in 1.47. We don’t see the issue in 1.46 but start seeing it in 1.47.

It seems to be related to this issue:

I updated the issue with an animate gif of our problem and a brief description.

Thanks for tracking this down and updating this thread Ashley! Now that I think about it, I wonder if this issue is specific to logarithmic depth buffers. Can you try turning it off:

viewer.scene.logarithmicDepthBuffer = false;

``

And see if that fixes it?

If not, I wonder if simply reverting the change in that file in your own CesiumJS build will fix it. It would mean extra work in maintaining it/merging it with new updates if turning off log depth doesn’t solve it.

logarithmicDepthBuffer = false; seems to fix it. Thanks!