Assigning Level to References

                This blog is about assigning levels to references, a less popular option in reference Attachment settings dialog. Like assigning a level to graphical elements like lines and arcs, you can assign a level to references too. Before starting on benefits and usages of this option, let me give you some background about this setting.
Historically, this feature was implemented to support AutoCAD compatibility. So, this option was enabled only when working with dwg files. It was controlled by the following two capabilities.

1. CAPABILITY_REFERENCE_ATTACHLEVEL
2. CAPABILITY_REFERENCE_VIEWLEVELDISPLAY

Starting from MicroStation V8i, this feature is enabled by defauly for all files.

How to use "Level" option

                Let us say we are modelling a 10 floor building and we have separate models for different components. Let's say, Plumbing, Electrical and Walls models contain geometry about plumbing, electrical and walls respectively. Each model has many numbers of levels to represent different floors. E.g. Level ‘Plumbing F-1' has all details of plumbing network at 1st floor.

                Now, we attach all three models into Design Composition model and then, this model to final sheet model. Refer Image-02 for the reference level hierarchy.

                With so much detail about each component, many times it is hard to understand final sheet or it is required to hide some of the details in sheet. As we didn't use any specific level while placing attachments, now it is difficult to hide specific details from sheet. The only way to do this is to turnoff display of each level in plumbing model (In Level Display dialog, selecting appropriate reference model from the tree.

                Instead, if we place attachments on right levels as described in the diagram below, it becomes easier to manage the final model. If all plumbing details go to PLUMBING, Electrical details to ELECTRICAL and Walls details to WALLS level, then we just need to turnoff one level to hide the entire detail of the component.

Placing references on desired level makes the final sheet easier to manage and understand.

Another benefit of attaching reference to a level is "Saved View" can capture the reference display state. If we put a reference on a level and create saved view for following two cases

1) Turn OFF level on which reference was placed and create Saved View 1.

2) Turn ON level on which reference was placed and create Saved View 2.

Apply Saved View 1 and notice that reference is hidden. Apply Saved View 2 and notice that reference is displayed. This way we can store the reference display state in a savedview.

More blogs are comming up so be there.