DWG Open Options Dialog, Basic

Setting	Description
Architectural or Engineering Units	Defines the linear units for MicroStation to use when opening DWG files with Architectural and Engineering Units (LUNITS=3 or 4). For DWG files with these units, 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. MicroStation's system for controlling units is very flexible, but it depends on knowing the true geometry size. In AutoCAD, the true size of geometry in a DWG file is more ambiguous. You must set the Units options correctly to remove this ambiguity and enable MicroStation to correctly determine the true size of the DWG geometry. To set the units properly, you must understand the DWG file content and the standards used to create it. Generally, when you set units to an explicit unit value (for example, to Inches or Meters), these units become the master units when the DWG file is opened. The next smallest units on the units list become the sub units. For example, if Feet are the master units, Inches are the sub units. However, if the units you select are either the master or sub units of the DGN seed file, both the master and sub units from the seed file are retained. If you want to use the sub units of the seed file as the master units for the file that you are opening, you must change the units in the seed file. Values for units options include: Seed File Master Units — Specifies the master units in the DGN seed file. Seed File Sub Units — Specifies the sub units in the DGN seed file. Design Center Units — Specifies the units used in the DWG file being opened. If the AutoCAD system variable INSUNITS is appropriately set in the DWG file, set the units value to Design Center Units to ensure that the units are consistent when the file is opened in MicroStation. Beginning with release 2000, AutoCAD uses the INSUNITS system variable to specify units for Design Center blocks that are inserted into existing drawings. The INSUNITS variable allows for the type of automatic scaling that MicroStation performs when True Scaling is specified. However, this variable does not exist in AutoCAD files created prior to release 2000, and may be set inconsistently in files from more recent versions. Microinches Mils Inches Feet Yards Miles Micrometers Millimeters Centimeters Meters Kilometers
Decimal, Scientific or Fractional Units	Defines the linear units for MicroStation to use when opening DWG files with Decimal, Scientific or Fractional Units (LUNITS=1, 2, or 5). The unit options are the same as for files with Architectural and Engineering Units. The default setting is "Design Center Units". MicroStation's system for controlling units is very flexible, but it depends on knowing the true geometry size. In AutoCAD, the true size of geometry in a DWG file is more ambiguous, particularly in files with the linear units set to Decimal, Scientific or Fractional 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.
Unspecified Design Center Units	Defines the units for MicroStation to use when a DWG or DXF file being opened has its Design Center Units set to "Unspecified." The unit options are the same as for files with Architectural and Engineering Units, except that they do not include Seed File Master Units, Seed File Sub Units, or Design Center Units. The default setting is Meters.
Preserve MicroStation Settings	If on, 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. These settings include the active angle, active scale, and default tool settings. Some elements may also have MicroStation-specific data, such as a graphic group number, that does not exist in the DWG format. 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.
DGN Seed File	Sets the path and the filename of the seed DGN file. To browse for this file, click the Value column. 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. These settings may include default values for all MicroStation tool settings, active angle, active scale, tentative point display mode, and view attributes such as text nodes on/off. A DWG file does not have unit resolution. When a DWG file is opened in MicroStation, the resolution in the DGN seed file is used. You may set resolution in your DGN seed file for opening a DWG file. When saving a DGN file to DWG, the same resolution in the seed file will be used upon opening the DWG in MicroStation. Therefore your original resolution may be different. In general, the storage Resolution value in the seed file is insignificant. This setting determines the number of positional units per AutoCAD unit. The default seed file uses a storage resolution of 10000.
Model Space > Create 2D Models for Model Space	If on, creates a 2D model to represent model space. Use this setting when you know that the model contains only 2D geometry in the XY plane. If 3D geometry is present, it is flattened to the XY plane.
Model Space > Design Background Color	Opens the Select RGB color dialog, which is used to set the background color that MicroStation uses for the design model ("model space").
Paper Space > Create 2D Sheets for Paper Space	If on, creates 2D sheet models to represent paper space sheets. Use this setting when you know that the paper space models contain only 2D geometry in the XY plane. If 3D geometry is present, it is flattened to the XY plane. Note that the viewports of a 2D sheet model can contain views of 3D models, so it is not necessary to have 2D models to use 2D sheets.
Paper Space > Sheet Background Color	Opens the Select RGB color dialog, which is used to set the background color of the sheet model ("layout").

Architectural or Engineering Units

Defines the linear units for MicroStation to use when opening DWG files with Architectural and Engineering Units (LUNITS=3 or 4). For DWG files with these units, 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.

MicroStation's system for controlling units is very flexible, but it depends on knowing the true geometry size. In AutoCAD, the true size of geometry in a DWG file is more ambiguous. You must set the Units options correctly to remove this ambiguity and enable MicroStation to correctly determine the true size of the DWG geometry. To set the units properly, you must understand the DWG file content and the standards used to create it.

Generally, when you set units to an explicit unit value (for example, to Inches or Meters), these units become the master units when the DWG file is opened. The next smallest units on the units list become the sub units. For example, if Feet are the master units, Inches are the sub units.

However, if the units you select are either the master or sub units of the DGN seed file, both the master and sub units from the seed file are retained. If you want to use the sub units of the seed file as the master units for the file that you are opening, you must change the units in the seed file.

Values for units options include:

Seed File Master Units — Specifies the master units in the DGN seed file.
Seed File Sub Units — Specifies the sub units in the DGN seed file.
Design Center Units — Specifies the units used in the DWG file being opened. If the AutoCAD system variable INSUNITS is appropriately set in the DWG file, set the units value to Design Center Units to ensure that the units are consistent when the file is opened in MicroStation. Beginning with release 2000, AutoCAD uses the INSUNITS system variable to specify units for Design Center blocks that are inserted into existing drawings. The INSUNITS variable allows for the type of automatic scaling that MicroStation performs when True Scaling is specified. However, this variable does not exist in AutoCAD files created prior to release 2000, and may be set inconsistently in files from more recent versions.
Microinches
Mils
Inches
Feet
Yards
Miles
Micrometers
Millimeters
Centimeters
Meters
Kilometers

Decimal, Scientific or Fractional Units

Defines the linear units for MicroStation to use when opening DWG files with Decimal, Scientific or Fractional Units (LUNITS=1, 2, or 5). The unit options are the same as for files with Architectural and Engineering Units. The default setting is "Design Center Units".

MicroStation's system for controlling units is very flexible, but it depends on knowing the true geometry size. In AutoCAD, the true size of geometry in a DWG file is more ambiguous, particularly in files with the linear units set to Decimal, Scientific or Fractional 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.

Unspecified Design Center Units

Defines the units for MicroStation to use when a DWG or DXF file being opened has its Design Center Units set to "Unspecified." The unit options are the same as for files with Architectural and Engineering Units, except that they do not include Seed File Master Units, Seed File Sub Units, or Design Center Units. The default setting is Meters.

Preserve MicroStation Settings

If on, 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. These settings include the active angle, active scale, and default tool settings. Some elements may also have MicroStation-specific data, such as a graphic group number, that does not exist in the DWG format.

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.

DGN Seed File

Sets the path and the filename of the seed DGN file. To browse for this file, click the Value column.

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. These settings may include default values for all MicroStation tool settings, active angle, active scale, tentative point display mode, and view attributes such as text nodes on/off.

A DWG file does not have unit resolution. When a DWG file is opened in MicroStation, the resolution in the DGN seed file is used. You may set resolution in your DGN seed file for opening a DWG file. When saving a DGN file to DWG, the same resolution in the seed file will be used upon opening the DWG in MicroStation. Therefore your original resolution may be different.

In general, the storage Resolution value in the seed file is insignificant. This setting determines the number of positional units per AutoCAD unit. The default seed file uses a storage resolution of 10000.

Model Space > Create 2D Models for Model Space

If on, creates a 2D model to represent model space. Use this setting when you know that the model contains only 2D geometry in the XY plane. If 3D geometry is present, it is flattened to the XY plane.

Model Space > Design Background Color

Opens the Select RGB color dialog, which is used to set the background color that MicroStation uses for the design model ("model space").

Paper Space > Create 2D Sheets for Paper Space

If on, creates 2D sheet models to represent paper space sheets. Use this setting when you know that the paper space models contain only 2D geometry in the XY plane. If 3D geometry is present, it is flattened to the XY plane. Note that the viewports of a 2D sheet model can contain views of 3D models, so it is not necessary to have 2D models to use 2D sheets.

Paper Space > Sheet Background Color

Opens the Select RGB color dialog, which is used to set the background color of the sheet model ("layout").