Working in a MicroStation8-deliverable Project

Danger: Mixed Seeds for Mixed Versions

Multiple versions or formats can cause problems!

Mixed Versions Require Translations (they're internal and appear seamless, but there are potential issues)!

WARNING: if you are upgrading a file from MicroStation/J to v8 format you will be prompted for units:  Metric, International Foot or US Survey Foot.  Make sure you pick the right Foot definition as it does make a difference.

MicroStation/J's integer-based coordinate system was unitless.  The folks at Bentley decided they wanted to have English and Metric scale automatically so MicroStation v8 by default stores coordinates internally as metric.  International Foot and US Survey foot are defined differently and are translated differently into metric.  This can cause problems.

According to Caltrans, http://www.dot.ca.gov/hq/oppd/cadd/rsc_files/webpage.php, "At Caltrans, the MicroStation Units.def file has been edited for U.S. Survey Foot as the English unit."

Verify your project seed file and unit prior to translating (the San Diego seed files are linked below).

Danger:  Referencing isn't Flawless

If your seed file is v8, referencing Ms/J and DWG files does require a translation, Coincident and Coincident-World may lead to differing results.

There are a number of potential issues when using MicroStation v8 File Referencing:

• MicroStation v7 and AutoCAD do "translate" coordinates to the v8 settings
• Global Origin can make a difference

Reference Attach: Coincident vs. Coincident World

When in MicroStation v8 and Attaching a v7 Reference file the file attaches differently (it shifts!) when using Coincident vs. Coincident World.  Apparently "Coincident" is the better option (at least for the 805 project).

According to the MicroStation Help:

To align the reference with the active model with regard to both Global Origin and design plane coordinates, select Coincident - World in the Orientation list box. This option is available only when referencing a model in a DGN file.
or
To align the reference with regard to design plane coordinates only, select Coincident in the Orientation list box.

v7 files in MicroStation v8 

Our San Diego Transportation Group configuration is set so that ms/J dgn files remain ms/J format, even though we are running MicroStation v8:

• MS_OPENV7=3 (allows automatic loading and writing in v7 mode; does not change ms/j file format).

Using v7 files for v8-deliverable project

In theory if we have v7 heathen among the v8 pure then there is potential for mis-translation.  In theory, we should isolate the v7 or at least stigmatize them (with a "v7" prefix or suffix) to intrinsically flag the potential issue.