Navigating Levels in MicroStation V81 Mar, 2003 By: James Dyer
Within MicroStation, each element in a model is on a drawing level. Levels are analogous to transparent overlays: In different combinations, they make it easier to see parts of a model. With the ability to incorporate an unlimited number of levels in a DGN file comes the need to easily structure and control all aspects of levels.
This month, I'll provide an essential overview of the key operation of the Level Display dialog available in MicroStation V8, as shown in Figure 1.
Figure 1. MicroStation V8 offers many options for level control and management.
View Display Options
MicroStation V8 introduces three types of On/Off switches that can be toggled by selecting the View Display option button from the Level Display Dialog.
The View Display option should be used to turn levels On or Off in the views you specify, from 1 to 8. This is the most commonly used switch for MicroStation workflows. If you don't work with DWG data and prefer to keep things as simple as possible, then this is the only switch you'll need.
The Global Display option turns off a level in all views and all models. In order to see the contents contained on the levels, both Global Display and View Display must be set to the ON setting. Global Display can be very useful for turning OFF levels across the entire file. If you are working with DWG data, this display-control switch will provide more control than View Display provides.
The Global Freeze is similar to Global Display, except it also turns off the display of the elements within shared cells. This switch is mainly provided for display control of hybrid data (DGN and DWG). If you plan on working with hybrid data, you will want to be aware of this switch.
Should you wish to quickly turn on or off levels, you can use the following key-ins: on=all and off=all. To apply this key-in to all views, change them to read: on=all;selview all.
The Change Level tool allows you to interactively manipulate the attributes of a level by selecting elements. The level attributes include Display Off, Display Only, Lock, and Unlock. For added convenience, the Change Level tool supports selection sets and fences, which allows you to turn off many levels in one step.
If you want to see a particular level and turn off all others, choose the Display Only mode, as shown in Figure 2. When an element is selected with this mode, all the other levels are turned off except for the level of the selected element.
Figure 2. You can use the Change Level Dialog box to see a particular level and turn all others off.
The Lock and Unlock mode of the Change Level tool will lock or unlock the level of the selected element.
The Set Target mode will select the element's model in the Target Tree in the Level Display dialog. This allows quick access to a particular set of levels and is a great way to graphically identify reference attachments.
The Level Display Target Tree
The Target Tree shows the active model and all references as a tree. After selecting a target, its levels are displayed in the levels list. The tree supports multiple selection. When more than one target is selected, the sum of their levels is displayed.
Targets with references can be expanded or collapsed by clicking on the + or - icons in the tree. When a target is expanded, you can independently select the levels within the references. If a target is collapsed and selected, all of the levels from the target and its references are displayed.
Additionally, you can toggle the display of references by performing a right-click on a Reference in the Target Tree and selecting Reference On or Reference Off.
The following key-ins can be used to control the display of reference levels:
- Turn on/off levels and select the file: reference levels on/off.
- Turn on/off all levels and select the file: reference levels on/off all.
- Turn on/off all levels for all references: reference levels on/off all.
Level Display Control Filters
Establishing an active filter allows you to work with fewer levels at one time. You can either establish a Level Filter in advance or create one interactively. To interactively establish a level filter, begin by selecting the Active Level Filter button and selecting Untitled. When the filter row appears, click in the Name field and type characters that identify the levels you wish to filter and press the Enter key. The only levels that will appear will be the ones that have those characters in them.
If you display the Filter Names in the detail pane, you can quickly turn On or Off many levels with just a few clicks. When a level filter name is highlighted in the list, the levels that pass the filter will be On. If one filter turns a level On, and another turns it Off, the On filter wins and the level is displayed.
Displaying SHX Fonts within MicroStation
One of the realities you face with many projects is that individual designers or engineers may use different tools or prefer different design tools based on the activity that they are currently engaged in. MicroStation V8 delivers an unprecedented level of data interoperability between DGN, DWG, and DXF design and engineering data.
On some occasions when you open a DWG file in MicroStation V8, you are unable to see any of the SHX fonts. The main reason is that MicroStation is not finding the location of the SHX Font. Therefore, you must identify the location where the SHX files are located. By default, MicroStation first uses the value of the MS_ACADDIR configuration variable to find AutoCAD support files. If this is unavailable, MicroStation uses individual control variables.
This can be accomplished quite easily by simply going to WorkSpace pulldown menu and selecting the Configuration option.
Figure 3. Workspace Configuration dialog allows you to find and display hidden SHX fonts when working with AutoCAD files.
Once the Workspace Configuration dialog, as shown in Figure 3, appears, select the DWG/DXF category followed by the AutoCAD SHX Font Directory control, which controls the MS_DWGFONTPATH variable. Highlight the Font Directory control item in the list and click on the SELECT button to identify the directory where you have the .SHX fonts stored.
Every text element in a DWG file must be associated with a text style. When placing text, be sure to use a text style. When a file saved to DWG format, MicroStation automatically creates a text style with the name Style-X (where X is the font name) for each text element without an associated text style.
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