Productivity Corner: Dimensioning Tools Keep Your Styles in Order

22 Nov, 2004 By: James Dyer Cadalyst

MicroStation's improved features make the job easier than ever

This month's Productivity Corner column will focus on documenting your designs with associative dimensions.

With the introduction of MicroStation v8 2004 Edition, dimensioning tools are combined and tool settings are expanded for quick access to settings commonly changed during dimensioning. The selection order for dimension points has been redesigned to give you an early dynamic display of the dimension. Previously you would have selected the start point, the location, and then the end point of the dimension. Now you select the start point and end point of the dimension, followed by the location.

Dimension styles -- those saved collections of dimensioning settings -- can be applied to dimensions at the time of placement. They are directly linked to a dimension; if you update dimensioning styles in a file, all the linked dimensions also update. Dimension styles are stored in either the design file or an external library.

Dimensioning Tools
Dimensioning tool use is defined in the tool settings at placement time (figure 1).

Figure 1. MicroStation's dimensioning tools.

I'll define the function of each dimensioning tool here, then explain each one in greater detail below.

  • Element Dimensioning: Dimension an element (line, line string, multiline, shape, circular arc, or circle). Associations can be made to elements, to components of complex elements and elements that are part of a shared or un-shared cell.
  • Linear Dimensioning: Dimension linear distance between two points.
  • Angular Dimensioning: Dimension angles.
  • Ordinate Dimensioning: Label distances along an axis from an origin (datum) along the ordinate axis (line along which the distances are measured).
  • Change Dimension: Change a dimension element to the active dimension attributes set in the Dimension Styles dialog box (dimension lines, extension lines, and text categories) or by selecting a dimension style in the Change Dimension tool settings.
  • Match Dimension Settings: Set the active dimension settings to another dimension's attributes.
  • Reassociate Dimension: Recreate a dimension's association. Reassociate individually, using a fence or selection set. The elements must appear in the view for reassociation to occur.

Element Dimensioning
Use Dimension Element, the first tool in the Dimensions tool box, to dimension several types of elements, including:

  • lines
  • line strings
  • multilines
  • shapes
  • arcs
  • circles

After selecting an element to dimension with this tool, you can choose from among several dimension types by clicking the Next button in the Dimension Element tool settings (figure 2), or by pressing Enter.

Figure 2. Dimension Element tool settings.

MicroStation's dimension settings let you set attributes for the level, color, weight, font, text height, and text width for the text components of dimension elements. If enabled, these attribute settings override the current active settings in the design file when you place dimension elements.

Text styles are also supported for dimensions. If you wish to use a text style for a dimension, select it from the Text Styles option list. The magnifying glass next to the option list allows you to access the Text Styles dialog box. Note that if you check the boxes for attributes such as color, weight, and font in the Dimension Settings dialog box, those specifications will override the features of a text style.

The Alignment options in the tool settings control the alignment of linear dimensions.

  • View: Parallel to the view x- or y-axis. This is useful when dimensioning 3D reference files with dimensions parallel to the viewing plane. ("Xv" denotes the view x-axis.)
  • Drawing: Parallel to the design plane x- or y- axis. The design's rotation determines the alignment axis for a particular dimension. ("Xd" denotes the design plane x-axis.)
  • True: Parallel to the element being dimensioned. The extension lines are at right angles to the dimension line.
  • Arbitrary: Parallel to the element being dimensioned. The extension lines are not constrained to be at right angles to the dimension line. This is useful when dimensioning elements in 2D "iso" drawings. Iso Lock must be on to accomplish this.

The Annotation Scale lock can be enabled for all dimension text. If this lock is on, the active annotation scale is applied to any dimension text that is placed.

Associated Dimensions
The other Dimension Element tool setting is Association Lock. This important feature appears as a setting for all the dimension tools. Its purpose is to associate the dimension you are placing with the points in the drawing that it dimensions. It ensures that if an element with an associated dimension is modified, the dimension is automatically updated to a new value that corresponds to the change. For instance, if you alter the length of a line you have dimensioned, the dimension changes to reflect the alteration. This is the same as modifying an element that was patterned with an associative pattern.

You must enable the Association Lock in the Locks area of the status bar to create associations to elements. The Association Lock must be enabled to place associated dimensions. Let's try it out.

Linear Dimensioning

The linear dimensioning tools (figure 3) are used to dimension the linear distance between two points (length).

Figure 3. The Linear Dimension toolbar.

Use linear dimensioning tools to set alignment and location in the tool settings. Start and end terminator styles can be selected. Text alignment, frame, prefix, and suffix can also be set. Icons in the tool settings determine the tool's performance. Select Multiple Elements lets you select multiple elements for dimensioning by drawing a line through them. Tools include:

  • Linear Size: Dimensions the linear distance between two points. Each dimension is computed from the end point of the previous one and is placed chained.
  • Linear Stacked: Dimensions the linear distance from an origin. The dimensions are stacked.
  • Linear Single: Dimensions the linear distance from an origin, but the dimensions are chained.

Angular Dimensioning
Tools in the Angular Dimensions toolbar (figure 4) are used to create angular dimensions.

Figure 4. The Angular Dimension toolbar.

  • Angle Size: Computes each dimension except the first is from the end point of the previous one. Start and end terminators can be selected. The Arc Symbol option lets you place arc dimension text with an arc length accent above. Text frame, prefix, and suffix can also be set.
  • Angle Location: Computes each dimension from the dimension origin. Tool settings also include a First Terminator option, which sets an optional terminator for the beginning of the first dimension line.
  • Angle Between Lines: Use to dimension the angle between two lines, two segments of a line string, or two sides of a shape.
  • Arc Size: Dimension a circle or circular arc, and each dimension is computed from the end point of the previous one.
  • Arc Stacked: Each dimension is computed from the dimension origin and stacked.

Annotation Scale
Annotation scale is set in the Model Properties dialog box. It defines the scale for text in a model to allow scaling to the desired size when printing.

The Lock icon is available in the Dimension Placement tool settings and in the Text category of the Dimension Styles dialog box, so you can apply it to dimension styles. Any dimension text placed in a model with the Annotation Scale lock enabled in the dimension placement tool settings automatically will be scaled by that amount at print time.

Creating and Modifying Dimension Styles
From the Dimension Styles dialog box, you can create, modify, and manage dimension styles. Access the Dimension Styles dialog box (figure 5) at Element / Dimension Styles or by selecting the magnifying glass icon from any dimension tool's tool settings.

Figure 5. The Dimension Styles dialog box.

The Dimension Style option list shows available styles and displays the active dimension style. There are tools for creating, editing, saving, and deleting dimension styles. An additional tool is:

  • Reset Style: Reverts settings to the previously saved style, canceling any overrides made to the original style.

Dimension styles can be set up in a design file that contains no elements. This design file is only used to store the dimension style definitions. This type of file is called a design library file or DGNLIB. An administrator can create a DGNLIB and make it available to users. You can import dimension styles from a DGNLIB by going to File / Import in the Dimension Styles dialog box. Or, the configuration variable MS_DGNLIBLIST holds a list of files that can be used as DGNLIB resources. These files are located automatically by MicroStation, and the styles contained in them are available for you to use. Administrators can make changes or additions to the DGNLIB file so the updates are available to everyone.

Once a dimension style from a DGNLIB is used, its definition is copied into the active design file. To update your dimension styles to the latest definitions contained within a DGNLIB, use the Dgnlib Update tool or the key-in:

dgnlib update dimstyles

The categories into which dimension settings (figure 6) are grouped are listed on the left side of the dialog box.

Figure 6. Dimension style settings.

To create a dimension style, follow these steps:

  • Select each category and add desired settings.
  • Click Create Dimension Style.
  • Add a name and description.

Note: When you change a named dimension style, any dimension with that style changes accordingly. If you have an element with dimensions that shouldn't change even if you update dimension styles later, be sure to set its active dimension style to none.

Dimension Settings
Dimension settings control the appearance and behavior of dimension elements.

Alternate Labels
In the Units category, this setting lets you define a separate dimensioning style based on the distance being dimensioned. You can dimension in subunits below a certain value and in master units greater than or equal to that value.

Dimension with Leader
The Dimension with Leader option (figure 7) eliminates the need to drop dimensions to create a leader to the dimension line.

Figure 7. Dimensioning with leaders.

Note: When this option is enabled, the Manual Location option lets you place the dimension text off the dimension line with a data point. If this data point is within the locate tolerance distance of the dimension line, the dimension text is placed without the leader line.

Place Note
These settings are used to set the appearance of the leader and text used by the Place Note tool. Leader type, terminator, text frame, and left margin can be set here.

  • In-line Leader: If this setting is enabled, the note uses a leader that is aligned with the text. You can specify its length, in working units.
  • Text Rotation: Sets the rotation of the text either horizontal to, vertical to, or in line with the leader line.
  • Horizontal Attachment: Defines how the note is attached to the leader.
  • Edit About: Sets the origin. If you edit the text, the text is edited about this point.

To see this, turn on the Text Nodes view attribute.

The justification controls set justification and specify where the leader is attached for multiple lines of text. As you change settings, the x and y graphic updates, previewing the justification and leader attachment. The top buttons control text justification. The buttons on the left and right sides define where the leader line is attached to the text.

The filled attribute of terminators is controlled in the Terminators settings. Previously, display of filled terminators depended upon the Fill view attribute.

When using cells as dimension terminators, the Uniform Cell Scale option in the Terminator Symbols category allows you to uniformly scale by the terminator width.

Dimensions Using Text Styles
To use a text style with a dimension style, use the Text Style option list in the Text category. The Text Styles dialog box can be accessed by clicking on the magnifying glass icon.

Note: The Width attribute setting has no effect on TrueType fonts. The settings in the attributes portion of the Text category will override text styles. If using text styles, turn off the attribute settings.

Stacked Fractions
TrueType font stacked fractions are supported on import from AutoCAD. If a dimension which includes stacked fractions is imported from AutoCAD, the fractions will remain stacked.

This concludes our overview of MicroStation v8 2004 Edition dimensioning tools. Next month we will continue our journey through MicroStation dimensioning with a look at dimension associativity and references, as well as the dimension auditing tools.

Until next time -- Enjoy MicroStation!

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