viewer.flyTo on billboards breaks zoom limits

[cguldner]

I feel like this may have been mentioned before, but the flyTo method doesn't respect the zoom limits. For my case particularly it is zooming in way closer than the desired max zoom for billboards, but I'm guessing it isn't limited to that.

In addition, if you fly to a billboard, it seems to break the max zoom, because after that, you can zoom to any zoom level in both 2D and 3D, and it won't restrict you. It doesn't break the min zoom, so you can't zoom out infinitely, but you can seemingly zoom in infinitely

[pjcozzi]

Thanks for the report, @burn123. Do you have a minimal code example to reproduce this?

[cguldner]

@pjcozzi
Here is a basic example. Look at the drill-down picking section.
In our app, it was on a marker/billboard, so it allowed us to then be able to zoom to any zoom level. In the example, it seems that it then changes how zoomed in you can be to wherever it flew

[pjcozzi]

Thanks for the prompt response!

[cguldner]

@pjcozzi I realized that the code example I gave didn't actually contain the code that shows it is broken.
This is an updated example.

[cguldner]

I traced the issue some, and I realized that part of the problem, specifically why the minimum zoom is broken, is this line of Viewer.js:

controller.minimumZoomDistance = Math.min(controller.minimumZoomDistance, boundingSphere.radius * 0.5);

I'm not sure why the minimum zoom would be updated programmatically, because this should be something left up to the user in my opinion. Also, maximumZoomDistance is never updated in this way, which makes me think that this was some code that was useful at one point, but no longer is, and wasn't removed properly.