Opening And Saving DWG Files In MicroStation V8


 Product:MicroStation
 Version:V8, XM, V8i, CONNECT, 2023
 Environment:N\A
 Area:DWG
 Subarea:Open

 

This Client Server article is republished in its entirety from 2002 for reference purposes.

By Bentley Technical Support Group
15 July 2002

MicroStation V8 accepts DWG files as a native format, usable without translation. There are a variety of settings and options to be considered when preparing to work with DWG files for the first time.

July 15, 2002 - MicroStation V8 can natively open and save DWG files. Before working with DWG files for the first time in MicroStation V8, there are a variety of options and settings to be considered. This article introduces these settings and provides suggestions for their best use.

Opening DWG files

When opening a DWG file, there are options to consider that affect how the file will appear in MicroStation. You can access the DWG options by either opening a file from the MicroStation Manager or by using the menu command File > Open.

To make the DWG Options button available, you must select a DWG or a DXF file type.

There are two tabs in the Open DWG Options dialog.

GENERAL TAB

Units

Architectural or Engineering Units-Defines linear units to use when opening DWG files with architectural and engineering units. For DWG files, the linear units are inches and are displayed as feet and inches. You should keep this option set to (MicroStation) inches unless you know that the AutoCAD unit conventions were ignored when the file was created.

Unit Options

Seed File Master Units-Based on the Master Units from DGN seed file.

Seed File Sub Units-Based on the Sub Units from DGN seed file.

Design Center Units-Specifies the units used in a DWG file. If this setting is available and accurately set in the DWG file, you can set both units options to Design Center Units. MicroStation can then automatically use this value to interpret the DWG units. This setting is not available in AutoCAD formats prior to AutoCAD 2000, and it is sometimes not set / not set correct in AutoCAD 2000 files (and up).
To find which units have been set in the Design Center from within MicroStation, open the .dwg / .dxf and from the Key-in window enter:
DWG UNITS
With that key-in a window will open showing you the units set in the Design Center and at the same time it will allow you to pick a different unit from the dropdown list.
By saving the file, those units will be saved as well for a next editing session. It is a good idea to reopen a file in case the (Design Center) units have been changed.
Changing the units using the MicroStation Working Units window does not work for .dwg  / .dxf files.

Decimal, Scientific or Fractional Units-Defines the linear units for MicroStation to use when opening DWG files with decimal, scientific or fractional units. The unit options are the same as for files with architectural and engineering units. For DWG files with these units, the actual units are not implied, but they are typically one of the metric units. Therefore, setting this value appropriately requires some knowledge of the units used to create the geometry in the file. If this value is not set correctly, MicroStation may misinterpret the size of geometry in the DWG file.

Colors-DWG files do not store a background color for either design models ("model space") or sheet models ("paper space"). This is the only place that the background color can be selected for the DWG file.

DGN seed file-Sets the path and the filename of the seed DGN file. To browse for this file, click the adjacent magnifying glass icon. When a DWG file is open, MicroStation extracts most of the settings directly from the DWG file. However, MicroStation settings that are not present in the DWG are extracted from the DGN seed file.


Figure 1: General Tab of the DWG Options dialog.

ADVANCED TAB

Line Weight Scale (mm/pixel)-This value controls the relationship between line weights in MicroStation and AutoCAD. MicroStation line weights are defined in pixels, whereas AutoCAD defines them by width in millimeters. The default value is .25 mm/pixel. Entering a larger value will cause wide lines in a DWG file to come in at lower line weights in MicroStation; a smaller value will cause wide lines in a DWG to come in at higher line weights.

Create 2D Models for Model Space-When selected, a 2D model is created to represent model space. This setting should be used only when the model is known to contain only two-dimensional geometry in the X-Y plane. If 3D geometry is present, it is flattened to the X-Y plane.

Create 2D Models for Paper Space-When selected, 2D sheet models are created to represent paper space sheets. This option should be used only when the paper space models are known to contain only two-dimensional annotation geometry in the X-Y plane. If 3D geometry is present, it is flattened to the X-Y plane. Note that the view ports of a 2D sheet model can contain views of 3D models, so it is not necessary to have 2D models in order to use 2D sheets.

Use Seed File Global Origin and Unit Resolution-This option is for using the global origin and unit resolution values from the DGN seed file (specified on the General tab). Use this option if the DWG file originated from a DGN file, and you plan to save the file as a DGN.

Saving a file as a DWG

When saving a file to a DWG in MicroStation V8, you can control how the file will appear. To access the Save As DWG dialog, select Save As from the File menu. Change the file type to .DWG and select the Options button.

 

Figure 2: Advance Tab of the DWG Options dialog.

GENERAL TAB

DWG Version-MicroStation can save files in most AutoCAD formats, going as far back as AutoCAD v2.6. You should save files in the most recent version, as older versions may not support everything necessary for optimum conversion.

Units-The Units selection sets the linear units used in the AutoCAD file. Although MicroStation allows you to select a different unit system at any time without changing the actual size of the model geometry, AutoCAD does not provide a convenient method for altering units. Therefore, it is important that you select the correct output units. If you select Master Units or Sub Units, MicroStation uses the master or sub units from the default model of the current file.

DWG seed file-Although most of the settings and geometry come from the DGN file, certain settings that are not in a DGN file come from the DWG seed file.

Level Display-MicroStation allows you to turn on and turn off levels either globally or on a per-view basis; AutoCAD allows only global control. If the Level Display option menu is set to Global, the AutoCAD layers visibility is controlled from the global setting and the levels that are turned off on a per-view basis are turned on in the AutoCAD file. If the Level Display is set to one of the eight views, the AutoCAD layers are not visible if they are turned off either globally or in that view.

Use Level Symbology Overrides-If on, this option saves the DGN file level symbology to the DWG file. The AutoCAD layers use the override colors, the DWG entity properties are by level. The resulting DWG file will appear exactly as the DGN file appears when level symbology overrides are in use.

Save References As DWG/DXF-When saving a DGN file as a DWG file, you must save all DGN references as DWG files to enable AutoCAD to resolve the references. If you turn on the Save References As DWG/DXF option, the DGN references are saved as DWG files.

Create Overlays for Reference Attachments (No Live Nesting)-If on, this option creates all reference attachments as overlays. Doing so disables live nesting in the DWG output file, which can be useful in files where live nesting is turned off for all attachments.

Convert MicroStation Fonts to AutoCAD Fonts-MicroStation supports TrueType fonts, AutoCAD SHX fonts, and the fonts stored in the resource file font.rsc. If you turn on the Convert MicroStation Fonts to AutoCAD Fonts option, MicroStation converts the fonts in font.rsc to AutoCAD SHX fonts. If AutoCAD is installed, the AutoCAD font directory will be used by default as the target directory for the converted fonts. You can change the target directory.

Non-Default Design Models-Defines how non-default design models are saved to DWG files. A DGN file can have multiple design models and sheet models. When a DGN file is saved to DWG, the default design model is saved to model space in the DWG file, and the sheet models are saved to drawing layouts (paper space). The settings for saving the non-default design models to DWG include:

Create Separate Files-If selected, each non-default design model is saved to a separate DWG file. The model name is appended to the design file name. Reference attachments to non-default models are saved to XREF inserts pointing to the new separate DWG files.

Create Paper Space-If selected, each non-default design model is saved to a drawing layout (paper space) in the DWG model that contains the default design model. Reference attachments are merged according to the Attachments to Non-Default Models setting on the References tab.

Ignore-If selected, non-default design models are not saved to a DWG file. Reference attachments are merged according to the Attachments to Non-Default Models setting on the References tab.

Drop Unsupported Line Styles to Components-If on, this option drops elements that use custom line styles not supported by AutoCAD to individual components.

Drop Unsupported Area Patterns-If on, any associative area pattern that is not assigned to a DWG hatch definition is dropped and saved to individual entities in the AutoCAD file using this option. This option can greatly increase the size of the output file, but it preserves the display of area patterns that would otherwise be omitted.

Preserve MicroStation Settings-If on, this option preserves MicroStation-specific settings in the DWG file. Many MicroStation settings do not exist in AutoCAD and, therefore, cannot be saved as settings in the DWG file. Use this setting if the DWG output file will be edited with MicroStation and you want to preserve the settings and element data between editing sessions. MicroStation-specific settings are saved to an XRECORD entity, and MicroStation-specific element data is saved as XDATA on each entity. If the output file will not be edited with MicroStation, then this data is not required and is ignored by other applications.


Figure 3: General Tab of the SAVE AS DWG Options dialog.

ADVANCED TAB

Create Regions From Closed Elements-Controls the type of AutoCAD entity that is created from a complex shape, circle, ellipse or shape element with more than four vertices. If set to Never (or 3D Only and the model is 2D), these entities are stored in AutoCAD files as closed polylines, circles or ellipse entities.

Create Polylines From 3- or 4-sided Shapes-Select Always to save shape elements to closed polylines or select Never to save them to faces.

Create Solids from MicroStation TriForma Forms-When set to Never, this option saves MicroStation TriForma forms to simple non-solid entities. When set to If MicroStation TriForma Loaded, this option saves the MicroStation TriForma forms to solid entities.

Line Weight Scale (mm/pixel)-Controls the relationship between line weights in MicroStation and AutoCAD. MicroStation defines line weights in pixels, while AutoCAD defines them by width in millimeters. The default value is 0.25 mm/pixel. Setting a larger value causes wide lines in a DWG file to receive lower line weights in MicroStation; a smaller value causes wide lines to receive higher line weights.

Line Code Scale (Design Units/Cycle)-Sets the scale value for MicroStation line codes. MicroStation's line codes (standard line styles 1-7) are defined in screen units and are independent of the view zoom factor. AutoCAD line type definitions are always defined in drawing units and are, therefore, not compatible with the MicroStation line codes. If Line Code Scale is set to the default value of 0.0, the lines will be scaled based on the size of the line codes in the first visible view. If the Line Code Scale is set to a non-zero value, this value represents the length (in DWG file units) of a single cycle of the line code pattern.

Construction Class Elements-Defines how construction class elements are written to DWG files.

Save-Saves construction elements to DWG in the same manner as primary class elements.

Omit-Does not save construction elements to DWG.

Save As Invisible-Saves construction elements to DWG as invisible entities.

Save To "Construction" Layer-Saves construction elements to layers with the original layer name followed by "(construction)." This is the default.

Save to "Defpoints" Layer-Saves the geometry to the Defpoints layer. AutoCAD typically uses this layer for dimension definition points and other construction geometry.

Pattern Class Elements-Defines how pattern class elements are written to DWG files. In MicroStation DGN files, element display can be controlled based on the element's class. MicroStation uses the pattern class for all area and linear pattern geometry. When linear patterning is applied to an element, the element class is changed to linear patterned. DWG files do not have analogous concepts. Associated patterns are saved as hatch entities and can be controlled (along with filled geometry) with the AutoCAD FILLMODE setting, but non-associative and linear patterns are saved as simple geometry and therefore have no such control.

Save-Saves pattern elements to DWG in the same manner as primary class elements. This is the default.

Omit-Does not save pattern elements to DWG.

Save As Invisible-Saves pattern elements to DWG as invisible entities.

Save To "Pattern" Layer-Saves pattern elements to layers with the original layer name followed by "(pattern)."

Save to "Defpoints" Layer-Saves the geometry to the Defpoints layer. AutoCAD typically uses this layer for dimension definition points and other construction geometry.

Linear Patterned Class Elements-Defines how linear patterned class elements are written to DWG files. In MicroStation DGN files, element display can be controlled based on the element's class. MicroStation uses the pattern class for all area and linear pattern geometry. When linear patterning is applied to an element, the element class is changed to linear patterned. DWG files do not have analogous concepts. Associated patterns are saved as hatch entities and can be controlled (along with filled geometry) with the AutoCAD FILLMODE setting, but non-associative and linear patterns are saved as simple geometry and therefore have no such control.

Save-Saves linear patterned elements to DWG in the same manner as primary class elements.

Omit-Does not save linear patterned elements to DWG. This is the default.

Save As Invisible-Saves linear patterned elements to DWG as invisible entities.

Save To "Linear Patterned" Layer-Saves linear patterned elements to layers with the original layer name followed by "(linear patterned)."

Save to "Defpoints" Layer-Saves the geometry to the Defpoints layer. AutoCAD typically uses this layer for imension definition points and other construction geometry.

Create Single Block for Duplicate Cells-If on, saves duplicate unshared cells to a single block with multiple inserts. To optimize the DWG file size, leave this setting on (the default). If this setting is off, each duplicate unshared cell is saved to a single block and single insert.

Note: DWG files do not support unshared MicroStation cells.

Create Scaled Blocks-If on, creates scaled block inserts within the DWG file. However, in some cases, it is not desirable to allow scaled block inserts. If this setting is off, the software creates only unscaled block inserts (scale = 1.0).

Code Page for DWG File-Defines the code page used by the DWG file.The operating system uses a code page to define fonts or characters for language support. Generally, you do not need to change the code page for the DWG file, since a code page is already defined for the operating system.

 


Figure 4: Advance Tab of the SAVE AS DWG Options dialog.

REMAP TAB

Controls how element parameters, such as levels, symbology, fonts or cell names are remapped to different values when the active file is saved to a DWG/DXF file. For example, you can remap elements on level "Floor Plan" of the active file to level "First Floor Plan" in the DWG file. Remapping is very useful when you save to DWG/DXF files, since current DGN files support more line styles than AutoCAD files. Remapping lets you decide how to handle differences between these types of files. Remapping is also useful when you need to convert standards to comply with organizational requirements, or to control output when you are using the Batch Convert utility.

To remap element parameters, use a remapping table. This table is saved in a CSV (Comma Separated Value) file that is created by a macro embedded in a spreadsheet program.

CSV file-Lists the CSV file that is used for remapping element parameters.

Browse for CSV remapping file-Opens the Select Remapping CSV File dialog box, which lets you select the CSV file to use.

Edit CSV remapping file-Opens the selected CSV remapping file as a spreadsheet in Microsoft Excel. The remapping file contains a worksheet for each type of parameter that can be remapped: levels, colors, weights, line styles, fonts, and cell names. Each worksheet represents a section in the CSV file. To edit the spreadsheet, pick the appropriate worksheet (for example, colors). In the first column of the worksheet (for example, color), enter or modify the value to be remapped. In the same row, enter or modify the new value in the DWG output column (for example, DWGOutputColor).

Create CSV remapping file-Opens the Create Remapping CSV File dialog, which lets you enter a name for the new CSV remapping file. Click OK, and the new CSV remapping file opens as a spreadsheet in Microsoft Excel. The remapping file contains a section for each type of parameter that can be remapped: levels, colors, weights, line styles, fonts and cell names. Each worksheet represents a section in the CSV file. To enter data into the spreadsheet, first pick the appropriate worksheet (for example, colors). In the first column of the worksheet (for example, colors), enter the value to be remapped. In the same row, enter the new value in the DWG output column (for example, DWGOutputColor).

Apply Level Mapping-When on, this option applies level mapping from the CSV remapping file when the open file is saved to the DWG/DXF file. This option will not be sensitive if the Levels section in the CSV file does not contain data.

Apply Font Mapping-When on, this option applies font mapping from the CSV remapping file when the open file is saved to the DWG/DXF file. This option will not be sensitive if the Fonts section in the CSV file does not contain data.

Apply Line Style Mapping-When on, this option applies line style mapping from the CSV remapping file when the open file is saved to the DWG/DXF file. This option will not be sensitive if the Line Styles section in the CSV file does not contain data.

Apply Color Mapping-When on, this option applies color mapping from the CSV remapping file when the open file is saved to the DWG/DXF file. This option will not be sensitive if the Colors section in the CSV file does not contain data.

Apply Weight Mapping-When on, this option applies line weight mapping from the CSV remapping file when the open file is saved to the DWG/DXF file. This option will not be sensitive if the Weights section in the CSV file does not contain data.


Figure 5: Remap Tab of the SAVE AS DWG Options dialog.

REFERENCE TAB

Controls how references are handled when you save a DGN file to a DWG or DXF file. The DWG file format does not support all the reference attachments possible in MicroStation.

External Attachments-Controls how standard attachments to the default model are handled when you save a DGN file to a DWG/DXF file. Generally, it is better to retain these types of attachments as XREFs (the default). You can also choose to merge the default model and its attachments into a single file.

Retain-Keeps the attachments to the output file. In AutoCAD, these attachments will be XREFs.

Merge-Merges the attachment geometry into the output file as individual elements.

Merge to Cell-Merges the attachment geometry into the output file as a single cell.

Omit-Omits the attachment from the output file.

Self Attachments-Controls how self-attachments are handled when you save a DGN file to a DWG/DXF file. A self-attachment is a reference attached to itself. AutoCAD does not support self-attachments. You must merge self-attachments to preserve their display.

Retain-Keeps the attachments to the output file.

Merge-Merges the attachment geometry into the output file as individual elements.

Merge to Cell-Merges the attachment geometry into the output file as a single cell.

Omit-Omits the attachment from the output file.

Non-Default Models Attachments-Controls how attachments to non-default models are handled when you save a DGN file to a DWG/DXF file. AutoCAD is limited to one default model per file with one or more sheets ("paper space" models) displaying views of that model. AutoCAD's XREF attachments can only display the default model.

Retain-Keeps the attachments to the output file.

Merge-Merges the attachment geometry into the output file as individual elements.

Merge to Cell-Merges the attachment geometry into the output file as a single cell.

Omit-Omits the attachment from the output file.

Masked Attachments-Controls how clipping masks in attachments are handled when you save a DGN file to a DWG/DXF file. AutoCAD does not support XREF's with clipping masks. Therefore, saving a masked attachment to a DWG file (Retain) removes any clipping masks applied to that attachment. When you use merging, the clipping masks are applied to the geometry as it is merged.

Retain-Keeps the attachments to the output file. In AutoCAD, these attachments

will be XREFs. The clipping mask will be removed.

Merge-Merges the attachment geometry, including the clipping mask, into the output file

as individual elements.

Merge to Cell-Merges the attachment geometry, including the clipping mask, into

the output file as a single cell.

Omit-Omits the attachment from the output file.

Copy Levels During Merge-Describes how levels are handled when you merge references from the DGN file into a DWG/DXF file.

If Not Found-Levels from the reference are merged into the output file only if they (or a level with the same name) do not exist in the active model.

If Overrides Exist-Levels from the reference are merged into the output file if the level does not exist in the active model, or if the settings for the active model level are different than those of the attachment. Differences include overrides that have been applied to the attachment levels, or differences between the levels as defined in the active model and reference.

Always-Levels from the reference are merged into the output file even if an identical level exists within the active model.


Figure 6: Reference Tab of the Save As DWG/DXF Options dialog.


Figure 7:Filter Tab of the Save As DWG/DXF Options dialog.

FILTER TAB

Contains controls that are used to filter the data that is saved to the output file.

Geometry

Fence Mode

Sets the Fence Mode that, in conjunction with the fence placement, defines the fence contents for manipulation.

Clip Volume

Specifies whether a clip volume is used to filter the elements to be saved.

If set to Ignore (the default), clip volumes are ignored.

If set to a view, only the elements within the view's clip volume are saved. The clip volume is defined according to the Fence Mode setting (Inside, Overlap, or Clip).

Models

Opens the Select Models dialog box, which lets you choose the models to save to the output file(s).

Auxiliary Coordinate Systems

If on, saved Auxiliary Coordinate Systems are saved to the output file.

Saved Views

If on, saved views are saved to the output file.

Shared Cell Instances

If on, shared cell instances are saved to the output file. If off, all shared cell instances are converted to normal cells in the output file.

Unused Shared Cell Definitions

If on, all shared cell definitions are saved to the output file. If off, unused shared cell definitions are omitted from the output file.

Named Groups

If on, named groups are saved to the output file. If off, named groups are omitted from the output file.

Frozen Levels

If on, the geometry on frozen levels is saved to the output file. If off, geometry on frozen levels is omitted from the output file.

Tags

If on, tag elements are saved to the output file. If off, tag elements are converted to simple text elements in the output file.

See also

Other language sources

 Original Author:Bentley Technical Support Group