Specialized Editing Commands

Within AutoCAD exist numerous commands that have been provided to edit very specific object types. These unique objects have characteristics that can be exposed through specialized commands made just for them.

Editing Attribute Values

There are two editing commands available that are used specifically on attributes contained within an attributed block. The commands are DDATTE and ATTEDIT, both of which are discussed in the following sections.

Using DDATTE on Attributes

If you want to change the text values of a variable attribute that is part of an inserted block, use DDATTE. This command is issued by choosing Single from the Attribute submenu. After selecting the block, the Edit Attributes dialog box is displayed. It shows the attribute prompts and the current text values of the attributes (see Figure 11.22).

If more attributes exist than can be displayed in the dialog box, use the Next and Previous buttons to display the additional sets of attributes.

Using –ATTEDIT on Attributes

Whereas DDATTE enables you to change the text values of attributes, the -ATTEDIT command enables you to change other properties of inserted attributes. -ATTEDIT is issued by selecting Global from the Attribute submenu. You are prompted whether you want to edit attributes one at a time. If you answer No, you can perform a text search-and-replace on the text string of the selected attributes. If you answer Yes to editing attributes one at a time, you can change the value, position, height, rotation angle, style, and color of the selected attributes.

Whether you answer Yes or No, you also have the option of filtering the selected attributes by block name, attribute tag name, or attribute value. The default value for all three filters is an asterisk (*), which indicates that no filters should be used and that the attributes the user selects are to be accepted.

There are a number of new commands for dealing with Attribute data. The new Enhance Attribute Editor and the Block Attribute Manager both extend new functionality that will greatly increase modification of attributes. If you are not familiar with attributes, see Chapter 9, “Understanding the Query Features in AutoCAD 2002,” for complete coverage of attributes and their use with blocks.

Editing External References

There are two editing commands available that are to be used specifically on external references: XBIND and XCLIP, both of which are discussed in later chapters. For additional information about blocks and external references, see the respective Chapters 13 and 14, “Creating and Using Blocks” and “Working with Drawings and External References Productively.”

Editing Raster Images

There are three editing commands available that are to be used specifically on images that are typically inserted as raster images: IMAGECLIP, IMAGEADJUST, and TRANSPARENCY. In addition to the commands, the system variables IMAGEFRAME and IMAGEQUALITY affect the display of images. The commands and system variables are discussed in the following sections.

Clipping Images

You can clip portions of an image just as you can clip the display of an external reference. The equivalent of XCLIP (used for xrefs) is IMAGECLIP, which is designed for use on images. To issue the IMAGECLIP command, choose Image Clip from the Object submenu. With IMAGECLIP you can define a new rectangular or irregular polyline clipping boundary. You can also use the command to turn on or off the clipping boundary. To display the clipping frame of all images, turn on the system variable IMAGEFRAME by choosing Frame from the Image submenu. If the frame is not displayed, you cannot select the boundary object.

Adjusting the Image

Several additional editing commands are available in the Image submenu. Choosing Adjust issues the IMAGEADJUST command and displays the Image Adjust dialog box (see Figure 11.23), in which you can adjust the brightness, contrast, and fade settings of the selected image.

You can accelerate the display of images by setting the system variable IMAGEQUALITY to the Draft setting. IMAGEQUALITY, accessed by choosing Quality from the Image submenu, affects only the display of raster images, not the plotting of images; raster images are always plotted at the high-quality setting.

Controlling Transparency

Some raster image file formats support a transparency setting for pixels. When transparency is enabled, the graphics on the display show through the transparent pixels of the overlaid raster image. By default, images are inserted with transparency off. You can turn this setting on or off for the selected images by using the TRANSPARENCY command, issued by choosing Transparency from the Image submenu.

Editing Multilines

The MLEDIT command is designed specifically to enable you to perform specialized editing operations on mline objects. To issue the MLEDIT command, choose Multiline from the Objects submenu. Figure 11.24 shows the Multiline Edit Tools dialog box.

With MLEDIT, you can clean up various types of intersections of two mlines, remove or add a vertex point in an mline, and insert or heal breaks in an mline. An overview of mlines is provided in Chapter 8, “Creating Polylines and Splines.”

Editing Polylines

The PEDIT command is designed for the editing of polylines and is issued by choosing Polyline from the Object submenu. With PEDIT, you can accomplish the following tasks:

• Create a polyline from a selected line or arc.

• Close an open polyline (Close option) or open a closed polyline (Open option).

• Join additional segments to the selected polyline (Join option).

• Change the polyline’s width (Width option).

• Set the polyline’s Ltype generation setting (Ltype gen option).

• Fit a curve to the polyline (Fit option).

• Fit a spline to the polyline (Spline option).

• Delete the curve or spline fitted to the polyline (Decurve option).

• Move, delete, or add vertex points in the polyline (Vertex option).

Enhanced in AutoCAD 2000i, the PEDIT command was broadened to allow multiple polyline editing. Polylines are covered in detail in Chapter 8, “Creating Polylines and Splines,” including this enhancement.

Editing Splines

The SPLINEDIT command is designed for the editing of splines and is issued by choosing Spline from the Objects submenu. With SPLINEDIT, you can accomplish the following tasks:

• Edit the fit points of the spline (Fit Data option).

• Open or close a spline (Open and Close options).

• Move the vertex points of the spline (Move option).

• Control the number or weighting of the control points (Refine option).

• Reverse the direction of the spline (Reverse option).

Splines are covered in detail in Chapter 8.

Editing Text and Mtext

The DDEDIT command enables you to edit text and mtext objects (as well as the value of associative dimensions). The DDEDIT command is issued by choosing Text from the Objects submenu. If a text object is selected, a single-line text editor dialog box is displayed. If an mtext object is selected, the Multiline Text Editor dialog box is displayed. The drawing and editing of text is covered in detail in Chapter 15, “Text Annotation.”