d e p a r t m e n t o f a r c h i t e c t u r e , u n i v e r s i t y o f o r e g o n
Symbols in AutoCAD: Blocks
April 15, 1997
A. Description
- A block is a compound object made up of entities + an origin point + a name. In a single drawing a single block definition may have many instances with different scale or orientation. A block may contain other nested blocks. A block may be a separate drawing file merged into the current drawing from outside. Any set of objects that gets drawn repeatedly should be a block.
B. Naming
- Block names should be well chosen to indicate contents.
- The ? option of BLOCK or INSERT will list the names of the blocks defined in the drawing.
- RENAME allows renaming of blocks
- Reuse of a block name results in redefining.
C. Defining
- Use BLOCK. Give a block name. Select a base (reference) point for subsequent insertions of the block. Select the objects that you want the block to include. Hit return. The objects will disappear. Use INSERT to bring them back as one entity.
D. Inserting
- INSERT creates an instance of a previously defined block.
- Select an insertion point, enter X,Y, and Z scale factors, or return for default value of any of these.
- Enter a rotation angle (about the insertion point) or return for O. Thus, to insert a block exactly as it was defined, just pick a position and hit return four times.
E. Unblocking
- EXPLODE replaces a block instance with the individual entities that comprise it. It does not affect the block definition.
F. Redefining
- When BLOCK is used to define a new object having the same name as a previously defined block, all instances of that block are automatically replaced with instances of the new one.