Issue while switching between tilesets

CesiumJS
1

Hi,

We are able to load the tilesets for each of the models that we currently have, the tiles and all the textures gets loaded, and it looks fine at first. But the issue arises when we keep on switching between the models (here while switching between one model to another we destroy the tileset of previously loaded before loading the next one) at some point or after few switches the tileset and textures of a particular model is not getting loaded fully instead only half or some part of the model gets loaded.

The current version of Cesium JS file is 1.112

Could please share some information on this particular issue for us to debug.

2

Hi Cesium Team,

Any updates on this post?
This issue is little critical and we cannot move further without fixing this issue.

We actually tried debugging and found that whenever this issue occurs, the Cesium JS is not fetching all the resources required to render a model from the server(i.e files such as materials, textures etc where all these are mentioned in tileset.json file). Suppose if there are 50 children in the tileset.json file, Cesium Js is not fetching all the 50 files, it is fetching 20 to 30 files from the server. This issue does not occur frequently but very few times while switching between the models. We also tried to do a possible work around using event listeners respect to the tiles loading but we could not succeed since the listener says it has finished loading all the tiles because this is based upon a scene it is saying whether all tiles loaded and not based upon the number of tiles that it has fetched when compared with tileset.json file.

We are looking forward for your response. Thanks in advance.

3

It’s hard to make guesses from the description so far, i.e. from the description of the symptoms, without details about the exact setup and application. But from the description so far: Do you see a message saying

The tiles needed to meet maximumScreenSpaceError would use more memory than allocated for this tileset.

showing up in the console at some point?

4

Hi Marco, Thanks for the response.

No error message as such nor any other exceptions when this issue occurs.

Below is the sample code for loading the tilesets,
tileset = viewer.scene.primitives.add(
new Cesium.Cesium3DTileset({
url: modelUrl,
clippingPlanes: clippingPlanes,
skipLevelOfDetail: true,
baseScreenSpaceError: 1024,
skipScreenSpaceErrorFactor: 16,
skipLevels: 1,
immediatelyLoadDesiredLevelOfDetail: false,
loadSibilings: false,
cullWithChildrenBounds: true,
dynamicScreenSpaceError: true,
dynamicScreenSpaceErrorDensity: 0.00278,
dynamicScreenSpaceErrorFactor: 4.0,
dynamicScreenSpaceErrorHeightFalloff: 0.25,
maximumScreenSpaceError: 16,
cullWithChildrenBounds: true,
cullRequestsWhileMoving: true,
cullRequestsWhileMovingMultiplier: 60
})
);

I am not able to post the entire code so I am just referring the code used to load the tilesets.

5

It is generally difficult to make guesses about the reasons for certain behaviors, just based on a description of the symptoms. And it becomes particularly difficult when the observed behavior cannot be reproduced reliably. (This sounds like some sort of race condition, but with many unknown details).

Maybe someone from the CesiumJS core team can make further guesses, or has ideas about how we could narrow down the search space here.