We would like to create TMS tilesets that only cover a small region (for example the size of a city). However, we are having odd results that seem to be related to the boundingbox.
We can successfully create a tileset that covers the globe, but when we try to display one that covers any size that is less than the full globe we run into the boundingbox issues.
If the boundingbox is larger than the area covered by the tileset Cesium throws missing image errors and no tiles appear. In some cases we can adjust the size of the boundingbox (by setting the rectangle in the TMS constructor) so that it is slightly smaller than the area covered by the tiles... and the tiles will appear. But in other cases we can only get tiles to appear if we significantly reduce the size of the boundingbox. This, however, results in many of the tiles that fall beyond the boundingbox being filtered and not being displayed.
We've been creating the tiles with Global Mapper. We recently attempted to use GDAL2Tiles, however we haven't had much luck with it either.