Exception handling

[TQtong]

Question

When I test by loading a wrong/bad service, any error that occurs makes the entire scene stop working. I don’t think that’s acceptable, since I have no way to know beforehand if my service will render correctly.

Supplemental Data

https://jsfiddle.net/tangqi/ez84tnx7/34/

Library Version

0.4.21

Three.js Version

0.170.0

[gkjohnson]

Hello! Sorry for the delay - I've had to focus my time elsewhere but I'm trying to get back around to this project again.

Regarding error handling there's an event, which is listed in the API documentation, for detecting a failed tile content or tile set load. Is this not sufficient?

// Fired when a tile or tileset fails to load.
{ type: 'load-error', tile: Tile | null, error: Error, url: string | URL }

You can use it like so:

tilesRenderer.addEventListener( 'load-error', ( { url } ) => {

  // tile or tileset failed to load

} );

[TQtong]

My understanding is that even if incorrect content is loaded, it still should not affect rendering of the entire scene.

But in the current tests, when I use:

tilesRenderer.addEventListener( 'load-error', ( { url } ) => {

  // tile or tileset failed to load

} );

the rendered result is as shown in the figure (see screenshot).

https://jsfiddle.net/tangqi/ez84tnx7/46/

[gkjohnson]

My understanding is that even if incorrect content is loaded, it still should not affect rendering of the entire scene.

Can you explain what the issue is specifically in the screenshot? And what you expect it to look like instead? The overlay image coverage issue has been fixed in the most recent commits. And if a tile geometry cannot load then I'm not sure what we should expect to display, instead. You can use the resetFailedTiles function to reset the "failed" state of a tile so it will retry the requests.

This is what the example looks like in the main branch, now:

[TQtong]

I think that if a tile fails to load, it still should not affect the initial default basemap, or cause the whole globe to fail to render completely / properly.

[gkjohnson]

Am I understanding correctly that you're referring to an overlay image load failure causing the underlying map to not render rather than the actual tile geometry failing to fetch?

If so I agree the ImageOverlayPlugin should be more resilient to load failures. I think at least if an image fails to load then we should just skip rendering that image on the overlay. There may have to be some more complicated adjustments in order to allow for "re-fetching" and updating any affected tiles.

In what circumstances are you seeing image load failures?

[TQtong]

Yes, that’s what I mean. So far I’ve tested the following:

1. Requesting a service URL that does not exist
2. Sending a request with invalid or incorrect configuration
3. Calling the service under very poor network conditions