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Productivity Corner: Manage Your Design's Levels

15 Jun, 2005 By: James Dyer Cadalyst

Level Management provides flexibility in managing the display and final output of your designs


Cadalyst's MicroStation tips included in "Productivity Corner" are compiled by James Dyer and were tested using MicroStation V8 2004 Edition. Cadalyst welcomes MicroStation tips: E-mail them to james.dyer@bentley.com. By submitting a tip or code, you grant Cadalyst magazine the right to print and distribute your tip or code in print, digitally and by other means. Cadalyst magazine and the authors retain the rights to the tip or code, which are not to be downloaded or copied for commercial use.

MicroStation V8 2004 Edition introduces significant enhancements to the Level system. This month's Productivity Corner column will introduce you to a few of the most significant areas of enhancement. With MicroStation, instead of 63 numbered levels, you can manage an unlimited number of titled level definitions. When a level is created in MicroStation V8, a level element is created within the design file, just as a reference attachment results in a reference attach element. Once you create a level element, you can reference any design element to this level.

Level Manager
The Level Manager is the primary tool used to create and maintain level definitions (figure 1).

With the Level Manager you can:

  • Create, rename and delete levels
  • Set level-based symbology for ByLevel and Overrides
  • Create and manage level filters and filter groups
  • Create, import and export level libraries

You activate the Level Manager by selecting Settings / Level / Manager.

Additionally, you could access the Level Manager by adding the Level Manager tool, which is hidden by default, to the Primary Tools toolbar. Select the tool to open the dialog box or click the downward arrow next to it to open a pop-up version.

The number column in Level Manager, which is hidden by default, is the internal level number. The number column is similar to earlier MicroStation versions, providing support for key-ins that turn levels on and off (OF=1, 23, 52-63). By default MicroStation uses the original level number for imported V7 levels.

You can reassign the internal level number like any other level property. However, consider the limits if you plan to Save As a V7 operation on a file with more than 63 levels defined.

figure
Figure 1. Level Manager enables you to manage all display properties of levels.

Level Symbology
In addition to the usual active element attributes settings, you can place design elements with symbology settings inherited from the level where they are placed. The aforementioned is referred to as ByLevel symbology. ByLevel is an element attribute defined for a level in the Level Manager dialog box, which is applied to an element at placement time (figure 2).

figure
Figure 2. Define either ByLevel or Overrides symbology.

Should you wish not to inherit the level properties when placing elements, you can display all elements on a level with an alternate set of symbology using the Overrides setting. Overrides is a view attribute that you can use to alter the display of elements from their normal or ByLevel symbology appearance.

ByLevel Symbology
ByLevel controls element symbology, including color, line style and line weight. To use the ByLevel symbology associated with a level, select the ByLevel value from the Attributes tool bar or a tool's settings (figure 3).

figure
Figure 3. Color, style and weight attributes set to ByLevel.

Please note that if the ByLevel symbology definitions of a level are later changed, any elements on that level that were placed with the ByLevel attribute dynamically reflect the changes.

Override Symbology
As explained previously, each level can define a set of level symbology overrides. By default, levels are created with Overrides set to on and color, style and weight all set to zero. Overrides can be modified or disabled for color, weight and style for each level.

If you are familiar with MicroStation level symbology, you will recognize this functionality immediately. Unlike Level Symbology, which requires the global application of its settings, you can apply Overrides on a level by level basis. As with Level Symbology, the Override is controlled per view by the Level Symbology view attribute.

Because the Bylevel and Override symbology categories share the same attributes, the Level Manager segregates the display of these two symbology types by requiring the user to select one or the other from the Symbology menu.

Please note that Level Symbology must be turned on in the View Attributes dialog box for the Overrides symbology to display. Additionally, the ByLevel display of an element 'can't be turned off because it is an element attribute, not a view attribute. However, you can alter the display by changing the element attributes to something other than ByLevel or by using Overrides to temporarily change the display to the Override symbology.

The Styles tab in the Level properties dialog box lets you set ByLevel and Override symbology for custom line styles.

The Usage tab identifies where the level is used and gives a count for each element type that occurs on the level.

Working With Levels in Multiple Files
References and nested references are listed in a tree under the master file in the Level Manager dialog box. Simply right clicking on a reference opens a menu from which you can open the References dialog box or perform functions, such as Controlling Display or Detaching, which are available from that dialog box.

When you select more than one level at a time, it displays the levels from all the selected files. Since you can select multiple files, you can change symbology on levels that exist in multiple files.

Levels and References
As with many areas configuration variables provide tremendous help in managing levels in references and nested references. A few of the most important situations are presented below.

Controlling display of newly created reference levels:
Set MS_REF_NEWLEVELDISPLAY to 1 to display newly created levels in references.

Loading Reference File Filters:
MS_LEVEL_LOAD_ATTACHMENT_FILTERS loads level filters of reference attachments when the master file is opened. For every unique attachment by file, a top-level filter is created. This top-level filter represents the reference attachment. All filters of the reference attachment are loaded as children of this new top-level filter.

Turning off highlighting on reference manipulation:
By default, MicroStation highlights all elements in a reference file when the reference is manipulated. If MS_REF_DONTHILITEFORMANIP is set to any value, highlighting is disabled. Disabling speeds up the reference manipulations, but it makes it more difficult to see which references are being manipulated.

Resynchronize reference and library levels:
You can set MS_LEVEL_AUTO_SYNC_ATTRIBUTE_LIST so level attributes of library and reference levels are automatically resynchronized when a file is opened. Library levels are synchronized from the level library. Reference levels are synchronized from their source file.

All levels that come from the same nested file and share the same path also share the same attributes. Levels from the same nested file with different paths do not share the same attributes.

MS_LEVEL_EDIT_NESTED_ATTACHMENT_LEVELS lets you edit the attributes of levels in nested reference attachments.

If MS_NEST_COLORADJUSTMENT is set to any value, the nested reference color adjustments at each level are multiplied by this value. If not set, the color adjustment for the top-level reference controls the color adjustment for all nested references.

Active Level Option Menu
The Active Level Option list in the Attributes tool bar displays the current active level. When expanded, it lists the active level filter, including all levels in the filter (figure 4). If no filter is active, all the levels in the file are listed.

figure
Figure 4. The Active Level Options menu displays the current active level.

This indicates whether a level is used (bold text), if it is on (check mark), if it is locked (padlock -- if none is present, the level is unlocked) and its ByLevel color. Turn levels off by removing the check mark next to them. Unlock levels by clicking on the padlock.

MicroStation's level management provides incredible flexibility in managing the display and final output of your designs. Next month we'll continue our journey with level libraries, groups, filters and migration considerations.

Until next time -- enjoy MicroStation!


AutoCAD Tips!

Lynn Allen

Autodesk Technical Evangelist Lynn Allen guides you through a different AutoCAD feature in every edition of her popular "Circles and Lines" tutorial series. For even more AutoCAD how-to, check out Lynn's quick tips in the Cadalyst Video Gallery. Subscribe to Cadalyst's free Tips & Tools Weekly e-newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!
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