Computer Aided Engineering Drawing: Advanced Autocad Concepts

Computer Aided Engineering Drawing

Advanced AutoCAD Concepts Chapter No 5 Sir Syed University of Engineering & Technology Computer Engineering Department University Road, Karachi-75300, PAKISTAN

Text Book  Text Book:Mastering AUTOCAD 14

By George Omura  Course Outline is available at CAED course website.

Chapter Outline  Hatch  Printing Drawing  Dimensioning  DIM and DIM1  Layer  Block  Insert  W Block  Explode

 3D Drawing

3D Mesh  3D Poly  3D Array 

 VPoint

Hatch Command  The HATCH command is used to cross hatch or

pattern-fill an area.  

Format: Pattern

HATCH (? or name/U,style):

Hatch Command  Options  ?  name  U

 style

Lists the standard hatch patterns in acad.pat. Name of a hatch pattern. You are prompted for a scale and an angle for the pattern. Lets you define a simple pattern on the fly. You are prompted for an angle, the spacing between the lines, and a single or double hatch area. Defines what areas of the selected items are to be filled with the specified pattern, according to the following codes:

BHATCH  BHATCH -- Boundary Hatch Dialogue Box

 With the BHATCH command, you can hatch a

region bounded by a closed curve simply by pointing inside it. BHATCH automatically defines a boundary and ignores whole or partial entities that aren't part of the boundary.

Printing / Plotting a Drawing  Default device selection  Size and Orientation  Scale, Rotation and Origin  Advanced Option

DIM  The DIM command enters Dimensioning

mode, indicated by the Dim: prompt on the Command Line.  Enter a dimensioning subcommand, listed below, at the Dim prompt. You can abbreviate dimensioning subcommands to the capital letters indicated. Enter a space or at the Dim: prompt to repeat the previous subcommand.

DIM         

ALigned Linear dimensioning. ANgular Angular dimensioning. CEnter Draws center mark or center lines. Diameter Diameter dimensioning. HORizontal Linear dimensioning, horizontal dimension line. RAdius Radius dimensioning. ROtated Linear dimensioning at specified angle. STAtus Lists dimensioning variables and their values. VErtical Linear dimensioning, vertical dimension lines.

LAYER  The LAYER command lets you control which

drawing layer you are currently drawing on, and which drawing layers are displayed.  It also controls the color and linetype associated with each drawing layer. Format: LAYER  ?/ Make/ Set/ New/ ON/ OFF/ Color/ Ltype/ Freeze/ Thaw/ LOck/ Unlock: 

LAYER  Options  ? Wildname         

Lists layers, with states, colors and

linetypes. Make name Creates a new layer. Set name Sets current layer. New name, name Creates new layers. ON wildname Turns on specified layers. OFF wildname Turns off specified layers. Freeze wildname Completely ignores layers during regeneration. Thaw wildname "Unfreezes" specified layers. LOck wildname Disallows editing of specified layers. Unlock wildname Allows editing of specified layers.

LAYER  Where "wildname" appears above, the layer

name(s) can include "*" and "?" wild cards.  A single "*" selects all existing layers.

LAYER Control Dialogue Box  Both the DDEMODES and DDLMODES commands let

you control layers using the Layer Control dialogue box. The Layer Control dialogue box lists the layers in the current drawing, showing their properties. The layer states are indicated by single-letter codes as follows:    

FFrozen L Locked C Frozen in the current viewport N Frozen by default in new viewports

 You can select a layer in the list and change its

properties using the following buttons on the right side of the dialogue box:

BLOCK  The BLOCK command lets you name a group of

objects that can then be inserted, using INSERT, as a unit anywhere in the current drawing, with specified X and Y scales and rotation.  Format: BLOCK  Block name (or ?): Enter a name.  Insertion base point: Enter a point.  Select objects:

 If you respond to the "Block name" prompt with

?, AutoCAD lists the names of all Blocks currently defined in this drawing.

DDINSERT  DDINSERT -- Insert Dialogue Box  The DDINSERT command inserts a previously defined

Block or an existing drawing file as a Block Definition into your drawing.  Format: DDINSERT  When you issue the DDINSERT command, the Insert dialogue box appears.

INSERT  The INSERT command inserts one occurrence of a

defined Block into the current drawing at a designated point, applying scale factors and rotation. If the named Block is not defined in the current drawing, but another drawing exists with that name, a Block Definition is first created from the other drawing.  Format: INSERT  Block name (or ?) <default>:  Insertion point:  X scale factor <1> / Corner / XYZ:  Y scale factor (default = X):  Rotation angle <0>:

WBLOCK  The WBLOCK command writes all or part of a drawing

out to a disk file. WBLOCK sets the output file's HANDLES system variable to 1, and writes entity handles to the output file.   

Format: WBLOCK Filename: (output file name) Block name:

WBLOCK  Block Name Options  name  =

 *  (blank)

The named Block is written to the disk file. The named Block is written to the disk file, but the Block name is the same as the filename. The entire drawing is written to disk, except for unreferenced Block Definitions. Permits selection of individual objects to be written to disk. Also requests an insertion base point.

MINSERT  The MINSERT command is used to insert multiple

copies of a Block in a rectangular pattern, or array.  Format: MINSERT  Block name (or ?):  Insertion point:  X scale factor <1> / Corner / XYZ:  Y scale factor (default = X):  Rotation angle <0>:  MINSERT shares the prompt sequence above with the INSERT command, and functions in the same manner. Using MINSERT, however, you may not precede the Block name with an asterisk (*).

EXPLODE  The EXPLODE command replaces a Block reference

or associative Dimension with copies of the simple entities comprising the Block or Dimension, forms simple Lines and Arcs from Polylines, replaces 3D Polygon meshes with 3D Faces, or Polyface meshes with 3D Faces, Lines and Points.  

Format: EXPLODE Select objects Select Block reference, Polyline, Dimension, or Mesh.

3D Drawing  3D is an AutoLISP application (3d.lsp) that creates various

3D objects, including a box, cone, dome/dish, pyramid, torus, wedge, and a simple 3D mesh.  The 3D command creates each object as a polygon mesh rather than a series of 3D Faces, letting you edit each entity as a single object.  Use the EXPLODE command to turn these objects into a collection of 3D Faces.  

Format: 3D Box/Cone/DIsh/DOme/Mesh/Pyramid/Sphere/Torus/We dge:

3D MESH  The 3DMESH command lets you define a three-

dimensional Polygon mesh by specifying its M and N size, and the location of each vertex in the mesh. Vertices can be specified as 2D or 3D points.  The total number of vertices equals M times N.  Format: 3DMESH  Mesh M size: Enter a value.  Mesh N size: Enter a value.  Vertex (M,N): Select a point.  Vertices can be located at any distance relative to one another. After all vertices have been specified, AutoCAD draws the mesh.

3D Poly  The 3DPOLY command creates a general, three

dimensional Polyline.  A 3D Polyline consists entirely of straight-line segments connecting the vertices of the Polyline. You can supply 3D (x,y,z) coordinates for any or all of these vertex locations. Arc segments, width, taper, and other attributes of 2D Polylines are not supported.  Format: 3DPOLY  First point: Select a point.  Close/Undo/<Endpoint of line>:

3D Array  3DARRAY is an AutoLISP application (3darray.lsp)

that creates three-dimensional rectangular or polar arrays.  When you use the 3DARRAY command, you specify rows, columns, and levels for a rectangular array of objects or an axis for a polar array of objects.  Format: 3DARRAY  Select objects: Select objects to copy.  Rectangular or Polar array (R/P): Enter R or P.

VPOINTS  The VPOINT command asks you to select a 3D viewpoint, and

regenerates the drawing as if you were viewing it from that point.  All entities are drawn with the correct elevation and thickness, and projected as you would see them from the specified viewpoint.  Format: VPOINT  Rotate/ <current X, Y, Z>:  A viewpoint of 0,0,1 returns you to the normal 2D top or plan view. You can also use either VIEW Restore or ZOOM Previous to restore a prior view to the screen.  The VPOINT command doesn't work in paper space.

DDSOLPRM  DDSOLPRM -- AME Primitives Dialogue Box  " AME Primitives Dialogue Box" i.e

Advanced Modeling Extension Reference  The DDSOLPRM command allows you to create Box,

Sphere, Wedge, Cone, Cylinder, and Torus solid primitives using the AME Primitives dialogue box.  Format: DDSOLPRM

DDSOLPRM  Use the Baseplane area to create solid

primitives on a plane that is not the current UCS.  Baseplane defines the origin and orientation of the base (XY) plane of the solid primitive. When you select the On radial button in the Baseplane area, the Mode options described below become available.  The base plane remains in effect for the duration of the command.