2004

Table Of Contents
316 | Chapter 16 Draw Geometric Objects
To create a solid from the intersection of two or more other solids
1 From the Modify menu, choose Solids Editing Intersect.
2 Select the objects to intersect.
Create and Insert Symbols (Blocks)
A block is one or more objects combined to create a single object. Blocks help
you reuse objects in the same drawing or in other drawings.
Overview of Blocks
You can use several methods to create blocks:
Combine objects to create a block definition in your current drawing.
Create a drawing file and later insert it as a block in other drawings.
Create a drawing file with several related block definitions to serve as a
block library.
A block can be composed of objects drawn on several layers with various
colors, linetypes, and lineweight properties. Although a block is always
inserted on the current layer, the block reference preserves information
about the original layer, color, and linetype properties of the objects that are
contained in the block. You can control whether objects in a block retain
their original properties or inherit their properties from the current layer,
color, linetype, or lineweight settings.
You can use
PURGE to remove unused block definitions from a drawing.
How Blocks Are Stored and Referenced
To understand the operations, commands, and options that are available
with blocks, it is important to understand how blocks are stored and refer-
enced in a drawing. Central to working with blocks is understanding block
definition tables.
Every drawing file has an invisible data area called the block definition table.
The block definition table stores all block definitions, which consist of all
information associated with the block. It is these block definitions that are
referenced when you insert blocks in your drawing.
The following illustrations are conceptual representations of three drawing
files. Each rectangle represents a separate drawing file and is divided into two
parts: the smaller part represents the block definition table, and the larger
part represents the objects in a drawing.