Modifying a Block Definition

You can redefine block definitions in your current drawing. Redefining a block definition affects both previous and future insertions of the block and any associated attributes.

There are two methods for redefining a block definition in the current drawing:

The method you choose depends on whether you want to make changes in the current drawing only or in a source drawing also.

Modifying a Block Definition in the Current Drawing

To modify a block definition, follow the procedure to create a new block definition, but enter the name of the existing block definition. This replaces the existing block definition, and all the references to that block in the drawing are immediately updated to reflect the new definition.

To save time, you can insert and explode an instance of the original block and then use the resulting objects in creating the new block definition.

Updating a Block Definition That Originated from a Drawing File

Block definitions created in your current drawing by inserting a drawing file are not updated automatically when that other drawing is modified. You can use DDINSERT to update a block definition from the drawing file.

Updating a Block Definition that Originated from a Library Drawing (Advanced)

Content Explorer will not overwrite an existing block definition in a drawing with one that comes from another drawing. To update a block definition that came from a library drawing, use WBLOCK to create a separate drawing file from the library drawing block. Then, use DDINSERT to overwrite the block definition in the drawing that uses the block.

Note: Block descriptions are stripped off when using DDINSERT. Use the Windows clipboard to copy and paste a block description displayed in the BMOD dialog box from one block definition to another.

Modifying the Description of a Block

To modify the Content Explorer description of a block definition, use BMOD. You can also add descriptions to any number of existing blocks by choosing Apply in the Modify Block Description dialog box after entering each description.

Redefining Block Attributes

You can attach attributes to a block when you define or redefine that block. When AutoCAD LT prompts you to select the objects to include in the block definition, include the desired attributes in the selection set. Redefining the attributes in the block definition has the following effects on block references that were previously inserted:

For more information, see Attaching Data to Blocks.