Some of the tiles in few specific location is blinking

Sumit_Das · March 26, 2025, 3:16pm

I am using cesium with google api. In few locations it is blinking such as “latitude”: 46.797945936930276, “longitude”: -71.2280271161572,

Kevin_Ring · March 27, 2025, 3:44am

Hi @Sumit_Das, welcome to the community!

It sounds like you’re running into this issue:

github.com/CesiumGS/cesium-unreal

Weird occlusion culling problem

opened 11:04AM - 03 Nov 23 UTC

kring

bug

Originally reported on the community forum: https://community.cesium.com/t/tile…s-constantly-glitching-in-certain-zones/27648 In this one particular spot, near latitude 49.9889 longitude -113.410537, there's a very strange flickery visual glitch in Cesium World Terrain when you move the camera in close to the surface. The problem goes away when the Cesium3DTileset Actor is selected. It also goes away when you turn off Unreal's Occlusion Culling (Edit->Project Settings->Engine->Rendering->Culling). I believe what is happening is that Unreal is changing its mind every other frame about whether or not these tiles are occluded. So one frame they're rendered, the next they're not, and so on. If you do `r.VisualizeOccludedPrimitives 1` in the console, Unreal highlights these flickery tiles in green, indicating that they are occluded (at least some of the time): <img width="694" alt="image" src="https://github.com/CesiumGS/cesium-unreal/assets/924374/572cf1c9-f48c-49a9-acac-e30d3a891edb"> This is with "Suspend Update" enabled, so I don't think there's any possibility that we're accidentally toggling the tile's visibility on and off. I have no idea what's causing this occlusion ping-pong, though. Seems like it kind of has to be an Unreal Engine bug, but hard to say for sure. I tested with UE 5.1.1. ![occlusion-culling-artifact](https://github.com/CesiumGS/cesium-unreal/assets/924374/eb9551ca-ec96-42f0-b29d-2696e7a155ed)

We believe it is an Unreal Engine occlusion culling bug, but there are some possible workarounds listed in that issue.

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Some of the tiles in few specific location is blinking

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