Importing DGN Drawings

TPC Desktop Professional and Premium editions can import a DGN file into a drawing with levels, cells, polylines, etc. You end with a drawing much like you would if you had opened the file in any CAD program.

Once the drawing is imported, you can edit the drawing objects or convert them to survey points for stakeout.

From Drawing View, choose Tools | Import Data Into Drawing.
Choose Bentley DGN from the list of file types.
Choose Browse to locate the file you want to import and return to the Import dialog.
Choose Import. When TPC is done reading the file it displays ‘Finished’ in the status box. Close the Import dialog to see the imported file in the current drawing.
If you are importing the DGN file into a new drawing, untag all traverses in the Traverses Manager.
If the imported drawing is not displayed in Drawing View, choose View | Zoom | Zoom Extents.

TPC recreates the DGN file objects in the current drawing.

Importing Into a New Drawing

If you want to import the drawing as is into TPC, first create a new drawing from the Drawings Manager. You might want to create an empty drawing template and choose it, since things like the north arrow, title block and border are probably already included in the drawing you will import.

You may need to do a zoom extents more than once as TPC computes the positions of the imported objects.

Importing Into an Existing Drawing

When importing a DGN file into an existing drawing, TPC holds the current drawing extents, position and scale. Because of this, you might want to include the property boundary or portion of the right-of-way in the drawing before you import the DGN file.

Window Extents

Choose View | Window Extents to select the portion of the drawing you want to work with, then follow the command prompts on the status bar to select the diagonal corners of the extents window. TPC recomputes the scale at which the selected extents will fit on the page and centers the new drawing extents on the page. TPC may redefine either the horizontal or vertical extents in order to make the window fit the page.

Windowing the extent allows you to work with just the portion of the drawing you are interested in.

Converting Objects to Survey Points

One reason to import a drawing is to use the drawing objects in the survey. TPC can recreate coordinates for the drawing objects (end points of lines and arcs, insert points of symbols, etc). You might import a construction drawing, convert the curb lines to traverses, and then go stake them out. Or you could create survey points for all the light poles or storm drains.

Checking Construction Drawings

How many times have you started staking out a set of construction drawings only to find that things don’t match up like they should? CAD drawings often contain mistakes that show up in the construction surveying. Why? Because in CAD it’s easy to have hidden lines that aren’t the same length. It’s easy to accidentally move entities. It’s easy to do lots of things that make the data wrong but may not show up at a 1”=100’ scale.

Importing the drawing into TPC lets you check the closures, grades and inverses before you go out in the field. The result is that you catch the mistakes before the staking starts and everybody wins.

Existing Objects

When TPC imports a shared cell from a DGN file, it first checks to see if the drawing contains a corresponding block. This occurs when you import a DGN file into a drawing that you are already working on. If the imported shared cell is already part of the drawing, TPC defaults to the corresponding drawing block and ignores the imported block completely.

Editions

Professional