Composite iModels - Technical Preview

 

Previously in Infrastructure Cloud, all iModels are created utilizing web (or desktop) tools, and connections are created to synchronize engineering CAD files with a given iModel.  Although this hasn't changed, those (connected) iModels can now be leveraged further.

 

The best way to think about both types of iModels would be to refer to this diagram:

 

Composite iModels are composed of other iModels whereas Connected iModels are created from engineering CAD files.

 

One of the advantages of Composite iModels is that since they are created from existing iModels, the transformation is very fast.

 

When clicking the Create iModel button there is an option to create a Composite iModel:

 

 

After selecting the Composite iModel option, you are asked to give your iModel a name along with an optional description and image.

 

 

At this point, clicking the Create button creates an empty iModel.  You will then be presented with the transformation details page.

 

There are currently 2 transformation types:

 

Filtered

 

 

With the Filtered transformation you can use a Saved View from an existing iModel to create a new iModel. 

 

This requires the user to select an iTwin (current iTwin is the default), select an existing iModel from that iTwin project, if needed select an optional Named Version (if there are no Named Versions this is greyed out), and then select one Saved Views to use as the Filter.

 

 

 

Click on the Transform button to create your Composite iModel.

 

To update the target iModel, go to iModel Manager and click on the iModel tile's Context menu (the 3 dots) and select "Run Transform"

 

[Note: When updating the target iModel, the Saved View settings in the source iModel must be set to "Include New Content" (this is the default setting).]

 

 

Combined

You can also Combine existing iModels into a new iModel.  In similar fashion to Filter above, you will need to select an iTwin, then one or more iModels from that iTwin. For each iTwin you can select multiple iModels, and then clcik on the "+" button to add them to the configuration.

 

 

Notes on using Combine

 

The iModels you are combining need to share the same geospatial coordinate system. Otherwise, the Composite iModel graphics could become corrupted if these source iModels exist very far away from each other.

 

There are some rare cases where combining iModels can cause schema conflicts (the same objects in 2 different iModels with conflicting definitions).  In these cases, the secondary iModel with the conflict will be discarded and an error message will be written to the “Transform reports”.

 

There could also be duplicate elements when iModels are combined.  By default, the transforms will overwrite any previous elements with subsequent instances to avoid duplicates.  However, if these objects with the same element ids (FederationGuid) are graphically different, only the last version imported will be present.

 

When selecting the iModels, the order that you select them is important.  The first iModel you select will be used as the target iModel’s geospatial location.  Similarly for schema conflicts, the order processed will define which iModel has the “good” schema and which one contains the conflict.

 

Another scenario to be aware of is related to a recent update to allow editing the Combine configuration.  When using Filter to create multiple Composites from multiple Saved Views from the same source iModel, these generated Composites will have provenance to the original iModel.  This means that if combining these to another Composite they will "land" under the same original identifier and be viewed as the same source iModel.

This will not be a problem unless the User needs to remove one of the source iModels.  Since they all appear internally to be the same original iModel, the transformation will not be able to remove a single iModel without trying to then remove the rest.  This will generate an error trying to remove the source.

 

In this particular case, it would be better (and easier) to create a single Saved View for the Filter configuration.  The intended use of Combine is for iModels created via Connectors, as the provenance to these iModels is used in the Composite.

 

 

Transformation reports

Similar to the Sync reports for connected iModels, selecting the context (3 dot) menu on a Composite iModel, and selecting Manage Content opens a similar UI.  This allows you to re-run the transform, as well as select the report from the context menu for each transformation run.

 

The Transformation report is laid out in similar fashion to the Synchronization reports.