when zoom out or rotate viewer, my cesium model disappeared?

I have a very long model converted to b3dm type and load it using cesium sample code below:

var tileset = viewer.scene.primitives.add(new Cesium.Cesium3DTileset({

// url : ‘./tilesets/TilesetWithDiscreteLOD/’

url :’./tilesets/test/’

}));

tileset.readyPromise.then(function(tileset) {

viewer.camera.viewBoundingSphere(tileset.boundingSphere, new Cesium.HeadingPitchRange(0, 0, 0));

viewer.camera.lookAtTransform(Cesium.Matrix4.IDENTITY);

});

The issue is that when I zoom out or rotate viewer, the model disappeared.The result is below:

My ceisum model on the google drive url is :

cesium 1.3.9+win10+Chrome

Any helped would be greatly appreciated, thanks.

The tile is disappearing because its bounding volume is pretty small and is going out of view. It is the red area in the picture below (shown with tileset.debugShowBoundingVolume = true). Try making it larger to encompass the full model.

OK,thanks Sean.I made the bounding volume larger as below:
“boundingVolume”: {

“region”: [

2.097593752274169,

0.5337356166356161,

2.0997736731670527,

0.533743353294616,

-800.59912109375,

2044.27734375

]

The result like below:

It works better than before,but when I rotate the model,it is still disappearing sometimes.

like below:

Is the issue associated with sizeof bounding volume?

在 2018年3月8日星期四 UTC+8上午9:10:19,Sean Lilley写道:

I have refreshed my models and json file on google drive:

在 2018年3月8日星期四 UTC+8下午12:08:36,xuzhit…@163.com写道:

Ideally the bounding volume should enclose the model completely in all directions. It still looks like the bounding volume is very thin:

OK,Thanks very much.I will try making it fatter.

在 2018年3月9日星期五 UTC+8上午8:38:36,Sean Lilley写道: