Why this error is reported (and synchronization is not finished)?


I am trying synchronize quite simple 3D model, but this error is reported during the synchronization:

ERROR [0x0000475c] iModelBridge - Project extents are too narrow: 0.000000 (ratio of largest footprint dimension 
to height; expected greater than than 0.100000). Element geometry this expansive will affect display performance, 
and often indicates corrupt elements or transforms.

I do not understand what is wrong and how DGN file should be corrected.

With regards,


  • Hi Alain,

    As you know there are 7 versions of GCS marked as EPSG:5514.

    you are right, one EPSG code represents several variants of S-JTSK coordinate system. In fact, it's still the same system, but I guess usually with different Datum defined, which leads to different transformations to e.g. WGS 84.

    My guess is that when you speak of EPSG:5514 you are refering to Czech/JTSK-A.Krovak

    Yes. My experience is that when users for any reasons need to assign GCS in MicroStation, they typically select Czech/JTSK.Krovak or Czech/JTSK-A.Krovak.

    User-defined and external GCS could cause issues with the Connectors in some cases.

    No custom GCS is used.

    I would be grateful if you could provide a DGN with the GCS set and possibly a vector of any kind ranging over the apporximate area of the project.

    Because I am not allowed to share original data, I created own one: The content is different, but is placed at the same coordinates and I attached also some ItemTypes, because they are used in the original data too.

    The attached zip file contains 3 files with the same content:

    • iModelBridge JTSK test (no EPSG).dgn ... no GCS is assigned, synchronization works fine
    • iModelBridge JTSK test (EPSG 5514 JTSK).dgn ... EPSG:5514 Czech/JTSK.Krovak, the synchronization fails
    • iModelBridge JTSK test (EPSG 5514 JTSK-A).dgn ... EPSG:5514 Czech/JTSK-A.Krovak, the synchronization fails too

    So the problem is not whether delivered or custom GCS is used, but that the synchronization fails alwyas, when JTSK is assigned.

    With regards,


  • Jan,

    I had not forgotten about you. I was just caught up in a million things including grasping the whole iTwin process I am moderately familiar with.

    A safeguard for unknown GCS during publication of an iModel was added but was not required for EPSG:5014 with a locally built version of the Connectors. I beleive the issue was solved at the same time as another fix I had made earlier.
    There is one remaining issue I am investigating in Design Review that is specific to EPSG:5014 and it concerns display of Bing Map in Design Review. Bing will not display if opening the model is performed using a Saved View, It will display however when selecting the 3D Model tab instead. It may be related to the position of the Saved View or not. I will keep you posted.

  • Of course I meant EPSG:5514 above; not EPSG:5014.