ACIS and Parasolid 3D Modeling Kernel

AutoCAD's 3D Modeling Kernel, ACIS

MicroStation uses the Parasolid 3D Modeling kernel when solid models are incorporated into a design. However, when a DGN file containing 3D solids is saved to a DWG file, or a 3D DWG file is opened in MicroStation, the ACIS kernel is used to ensure accuracy and compatibility.

Blocks and Shared Cells

AutoCAD Block Definitions

In MicroStation, shared cells, which are similar to AutoCAD blocks, are used to insert predefined data blocks into a drawing. A shared cell can have many instances, but only one definition is stored in the DGN file. An unshared (normal) cell inserts the full definition each time the cell is placed. Thus, shared cells make cell replacement easier and the file size smaller.

Since any *.dgn or *.cel file can be used as a cell library, you can create an empty file to store cells. When cells are created, they are defined as either graphic or point cells. A graphic cell assumes the symbology from the elements contained within, while a point cell assumes the active symbology at the time it was inserted.

Coordinate Entry and AccuDraw

AutoCAD's Command Line Coordinate Entry for precise location of points

In MicroStation, use AccuDraw for precise drafting of geometry. To turn AccuDraw on and off, click the Toggle AccuDraw icon (compass) in the AccuDraw ribbon group. To customize the AccuDraw operation and display, use the AccuDraw Settings dialog. By using AccuDraw along with AccuSnap functions, you can develop an efficient and precise drawing technique.

Once AccuDraw and a drawing command are active, enter an initial data point, then the distances or angles to set the next point according to the compass displayed. The compass is either square or circular, depending on whether a rectangular or polar coordinate system is being used.

These are some of the many useful AccuDraw shortcuts:

Explode Command and Drop Tools

AutoCAD Explode Command

In MicroStation, use the tools in the Drawing > Home > Groups ribbon group to break elements into simpler components. The Drop Element tool is for general usage. It operates one level (layer) at a time, so that some elements must be dropped more than once. The ribbon group also includes specific drop commands for specific element types.

Xrefs and References

AutoCAD XREFs

In MicroStation, external files attached to the current drawing file are called references. The References dialog contains all the commands for attaching and operating on references.

Grips and Handles

AutoCAD's Selected-Object Grips

In MicroStation, when an element is selected, handles appear. These handles can be used to stretch an element (object). To turn off handle display, turn on Disable Handles in the Element Selection settings window.

Handles do not have associated right-click menus, and they cannot be used to move the element. To drag the element, enter a data point away from the handles, and move the pointer to the desired location.

BHatch and Patterning Tools

AutoCAD BHatch Command

In MicroStation, the Hatch Area tool generates a fill pattern of slanted lines at a defined angle and spacing. This tool does not have an associated palette of patterns. Any variation on the slanted lines is called an area pattern, and is generated by the Pattern Area tool. With Pattern Area, a cell from the current attached library is selected as the pattern to repeat. Pay close attention to the modes of application for repeated patterns displayed in the Method list on the dialog.

Both fill pattern tools are available in the Patterns ribbon group..

Object Selection

AutoCAD Implied Windowing

In MicroStation, you can designate selection sets before operating on elements (objects). To select elements:

• Use the Element Selection tool (pointer) to select an individual element, or select the tools and drag a rectangle (window) around multiple elements. While selecting elements, hold the <CTRL> key to add elements to a selection set or deselect an already-selected element.
• Use the Place Fence tool. A fence is a persistent window where you can set the shape and determine which elements are included, such as those completely inside the fence, overlapping, etc.
• Use a named graphic group of elements. With named groups, you can select multiple elements to be included, as well as control whether changes are propagated across the group or individually.

Object Snaps and AccuSnap

AutoCAD OSnap and Tracking

In MicroStation, use AccuSnap to select precise points on drawing geometry. When active (AccuSnap is on by default) , a yellow "X" highlights over elements and keypoints. Although there is no element (object) snap tracking in MicroStation, when AccuDraw is active, the cursor tracks to an axis on the AccuDraw compass (typically X or Y). The AccuSnap headings and toggle can be found Drawing > Drawing Aids > Snaps ribbon group.

Offset and Move/Copy Parallel Tool

AutoCAD Offset Command

In MicroStation, use the Move/Copy Parallel tool to move or copy an element parallel to the original.

Overlays

AutoCAD Overlay Type of Reference Attachment

In MicroStation, you create an overlay-type of file attachment by selecting the Ignore Attachment when Live Nesting setting in the Attachment Properties dialog.

MicroStation allows close control of Reference file nesting, including options for setting nesting depth, no nesting, and an overlay equivalent. These settings allow you to precisely select the data that is displayed when referenced files are nested, sometimes several levels deep.

Properties

AutoCAD Properties Window

In MicroStation, the Properties tool in the Primary ribbon group provides feedback for a selected element's general attributes and properties, as well as more detailed information. The information on the General tab, including level, color, style, weight, and class, can be modified in the dialog.

User Coordinate Systems and Auxiliary Coordinate Systems

AutoCAD UCS Command

In MicroStation, coordinate systems other than the file's default orientation and origin are called Auxiliary Coordinate Systems (ACS). You define an ACS through the Drawing > Drawing Aids > ACS ribbon group using an element, points, or a view.

The ACS triad is turned off and on from the View Attributes dialog.

To save and name auxiliary coordinate systems, use the Auxiliary Coordinates dialog.