Load Cesium resources

[BordeauxWind]

Question

I loaded the Bing base map of Cesium. If terrain is needed, there will be no problem.
tiles = new TilesRenderer();
tiles .registerPlugin(new CesiumIonAuthPlugin({ apiToken: token, assetId: '1', autoRefreshToken: true }));
tiles .registerPlugin(new TilesFadePlugin());

tiles .registerPlugin(new ImageOverlayPlugin({
renderer:renderer,
overlays: [new CesiumIonOverlay({
opacity: 1.0, assetId: '3',
apiToken: token,
})]
}));

However, if I don't want the terrain and only want to load the Bing base map, there will be a problem.
tiles = new TilesRenderer();
tiles .registerPlugin(new TilesFadePlugin());
tiles .registerPlugin(new ImageOverlayPlugin({
renderer:renderer,
overlays: [new CesiumIonOverlay({
opacity: 1.0, assetId: '3',
apiToken: token,
})]
}));
This way of using it is not correct. Could you please tell me what I should do? Thank you.

Supplemental Data

Library Version

0.4.18

Three.js Version

0.166

[gkjohnson]

Image overlays are only used for overlaying data on existing data sets and displaying Bing / quad key maps without providing a terrain is not currently supported. You can review how the XYZTilesPlugin works and adjust it to support Bing maps if needed:

https://github.com/NASA-AMMOS/3DTilesRendererJS/blob/master/src/three/plugins/images/EPSGTilesPlugin.js#L11-L30

In the long term I think it would be best to provide a "flat terrain" plugin that generates a smooth ellipsoid and plugins like "XYZTilesPlugin" should be deprecated.