ERROR output ".../tiles/3/0/1.glb" was not written by the subprocess

[Ylannl]

These errors appear in normal operation. Is it a problem? or should they be warnings?

[Ylannl]

I investigated this error. It can happen when the feature geometries are completely outside of the specified tile bounds. For example when grid-minz and grid-maxz are set such that the tile bounds do not intersect with a feature. This was the case for this specific tile and the recommended values for the grid min and max z.

Maybe we should add an option to no throw an error when no glb is written. No error output should be written during normal operation.

[balazsdukai]

Change error for missing tiles into warning. Add option to make warning for this an error.