Hello List

My original question was:

I am asking for any experiences that people might have about successfully
integrating Microstation design files into in ArcView 3.2a.  I want to be
able to do more than just look at them and import where necessary I would
actually like to be able to maintain all vector data as DGNs to reduce data
duplication and redundancy and also take advantage of the skills of the
Microstation operator who works in the office.

 I would appreciate any advice or stories and I am particularly keen to hear
about how to best enforce some reliable topological structure in DGN data,
the management of attribute tables to be linked to the DGNs and the best way
to automatically attach attributes these when loading a DGN to a View.
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I would like to thanks all those who responded, especially David Gifford.

This is an intermediate summary because I believe that there is still a lot
of work to be done.

Most of those who responded suggested conversion tools (such as Safe's FME)
or methods, and I believe that this was indicative in some way of the
problems that can be found in trying to maximise interoperability between
Microstation and AV3.2a.

One method that was provided by David Gifford was to establish standards on
what levels certain feature types were stored on in DGN files. i.e. One
thematic information source is stored in a design file (e.g. roads) and
different feature types are stored on separate levels (e.g. road type).
Look up tables can then be used to add attribution by joining them to the
design file using level (or colour) as the relate variable.

Joel Fuchs also suggested using the "element tags" available in Microstation
to add a greater level attribution which could be utilised by both AV and
Microstation.

Topology of polygons seems to be a more troubling aspect of
interoperability.  Much of the data captured in Microstation is done so with
only map presentation in mind so situations with a number of
"floating"/island/duplicated polygons occurs.  This is concerning especially
when I am unsure of what will result in every type analysis (intersect,
union, clip, area calculations, shape>grid conversions) with design files
structured in such a way.  One suggested work around which unfortunately
sees a duplication of data through a conversion process is the use of
Microstation product called Mappa (http://www.cartovista.com/) to cleanup
polygons or create them from line work in Microstation (analogous to clean
in ArcINFO) and attach any text found within the polygon to it via a common
field (MSLink) found within both the design file and a DBF file created
during the process.  The cleaned polygons are then converted to a shapefile
and then a spatial join done between the DBF file (which contains an x,y
centroid for the polygon) and the converted polygons to add the attributes
to the  shapefile's dbf.

Another few cautions came through from Uwe Lange and Joel Fuchs about what
"feature classes" can be used in AV and I direct you to see:
http://support.esri.com/search/KbDocument.asp?dbid=12031

My own experiences with "complex shapes" in design files also show that some
attribution is lost when viewing them in AV. For instance with 3D contour
design files, if they contain the contours as complex shapes then AV won't
see the elevation for all line segments only a small portion with the rest
having a value of "0". However if you go back into Microstation and drop
complexes all line segments will then have correct elevation values as far
as AV is concerned.

I am not completely up to speed with how to best work this process nor am I
highly experienced with Microstation and I am sure that many of you could
see how some of the data management techniques above would become very messy
with data sets that have complex attribution structures.  However,  it does
show some possibilities and I especially believe that through use of
standards and better communication between Microstation operators and AV
users better interoperability can be established.  There a couple of more
leads that I will be following up, so hopefully I will have some more to
provide to the list in the near future.  In the meantime I would like to
thank all of you who provided some input.

Best Regards,

Nick Middleton
Resource Information Analyst
Department of Agriculture
Albany, Western Australia.