Helix

Creates a 2D or 3D spiral.

1. Begin          a new drawing

2. Choose       Draw, Helix (or)

3. Type           HELIX at the command prompt

                        Command: helix

                        Number of turns= 3.000 TWIST= CCW

                        Specify center point of base: Pick point

                        Specify base radius or [Diameter] <1.000>: ENTER or Drag point

                       Specify top radius or [Diameter] <11.780>: ENTER or Drag point

                       Specify helix height or [Axis end point/Turns/Turn Height/tWist]<1.000>: ENTER or Drag point

UCS Icon

                    The UCS icon represents the orientation of the user coordinate system (UCS) axis and the location of the current UCS  origin. It also represents the current viewing direction relative to the XY plane. AutoCAD displays the UCS icon differently for 2D, 3D and paper space environments.

1. Choose      View, Display, UCS Icon                                                                                                                                                            (or)

2. Type        UCSICON at the command prompt

                     Command: ucsicon

                     Enter an option [ON/OFF/All/Noorigin/oRigin/Properties]<ON>:

                

ON                 Displays the UCS icon.

OFF               Turns off the display of the UCSICON.

All                  Affects the display of the UCSICON in all viewports.

Noorigin       Always displays the UCS at the lower left corner.

UCS Icon Properties

1. Choose      View, Display, UCS Icon,Properties                                                                                                                              (or)

2. Type        UCSICON at the command prompt

                     Command: ucsicon

                     Enter an option [ON/OFF/All/Noorigin/oRigin/Properties]<ON>: P

UCS Overview

                     The user coordinate system provides an alternate movable coordinate system for coordinate entry, planes of operation, and viewing. Most AutoCAD geometric editing commands are dependent on the location and orientation of the UCS. There are a variety of ways to set the User Coordinate System using the UCS command.

1. Type              UCS at the command prompt
                    Command: UCS
                    Specify origin of UCS or [Face/NAmed/OBject/Previous/View/World/X/Y/Z] <World>: 

 Face               Aligns the UCS to the selected face of a solid object.

Named          Saves or restores a UCS.

Object           Lets you define a new UCS by pointing at an object.

Previous       Restores the previos UCS.

New               Defines a new coordinate system by one of six methods: Origin, Z Axis,3 Point, Object, Face, View X, Y, Z.

View              Establishes a new UCS whose XY plane is perpendicular to your viewing direction (e.g. parallel to your screen)

World           Restores the world UCS

X/Y/Z           Rotates the ucs around a specified axis.

UCS Toolbars

Found under the AutoCAD Classic Toolbars

New (3 Point) UCS

The 3 Point option is one of the easiest ways to define a new UCS on a given 3D object.

1. Open        a drawing with a simple 3D object (Ex: BOX)

2. Type        UCS at the command prompt

                     Command: UCS

                     Specify origin of UCS or [Face/NAmed/OBject/Previous/View/World/X/Y/Z Axis] <World>: N

                    Specify origin of new UCS or [ZAxis/3Point/OBject/Face/View/X/Y/Z]<0,0,0>: 3

                    Specify origin point <0,0,0>: Pick point

                    Specify point on positive portion of X-axis <3.5,7.5,0>: pick point for X direction

                     Specify point on positive Y portion of the UCS XY plane<2.5,8.7,0>: Pick point for Y direction

New UCS

TIP:

You can also click the dropdown beside WCS and click New UCS.

World UCS

                The World UCS is only UCS guaranteed to be the same in all AutoCAD drawings and can be used to set the UCS back to its original state. This is the UCS you should use when creating Wblocks and inserting Wblocks.

1. Type        UCS at the command prompt

                    Command: UCS

                    Specify origin of UCS or [Face/NAmed/OBject/Previous/View/World/X/Y/Z Axis] <World>: W

Dynamic UCS

                     You can use the dynamic UCS to create objects on a planar face of a 3D solid without manually changing the UCS orientation.

                     During a command, the dynamic UCS temporarily aligns the XY plane of the UCS with a planar face of a 3D solid when you move the cursor over the face.

                     When the dynamic UCS is active, specified points, and drawing tools, such as polar tracking and the grid, are all relative to the temporary UCS established by the dynamic UCS.

1. Click                         the DUCS icon  on the status bar                                                                                                                                           (or)
2. Press                   CTRL+D
3. Type                    any draw command                                                                                                                                             Command: Circle
4. Move                   the cursor to the face of the 3D object on which you would like to draw. 
   
5. Click                    to begin drawing your new object.   
   
          

Viewcube

                     The ViewCube provides visual feedback about the current orientation of a model. The viewCube can help you adjust the viewpoint of a model. The orientation shown by the ViewCube is based on the North direction of the WCS for the model. The ViewCube also shows the current UCS and allows you to restore a names UCS.

Constrained 3D Orbit

                     3DORBIT  activates a 3D Orbit view in the current viewport. You can view your entire drawing or select one or more objects before starting the command.

                     When 3DORBIT is active, the target of the view stays stationary and the camera location, or point of view, moves around the target. However, from the user's point of view, it appears as if the 3D model is turning as the mouse cursor is dragged. In this way, you can specify any view of the model.

1. Open                    a drawing with 3D objects
2. Choose                 View, Orbit, Constrained Orbit                                                                                                                          (or)
3. Type                      3D ORBIT at the command prompt                                                                                                              Command: 3Dorbit
4. Click                      and drag to move your object in 3D.

Projection Mode

1. Click                     the right mouse button while in the 3D Orbit command
2. Choose                 perspective

                       Perspective view displays objects in perspective so that all parallel lines converge at one point. Objects appear to recede into the distance, and parts of the objects appear large and closer to you. The shapes are somewhat distorted when the object is very close. This view correlates more closely to what your eye sees.

                    Parallel view displays objects so that two parallel lines in a drawing never converge at a single point. The shapes in your drawing always remain the same and do not appear distorted when they are closer.

                        Perspective View                                                        Parallel View

Visual Styles

Displays your objects in one of the following selected styles:

1. Click                      the right mouse button while in the 3dorbit command.
2. Choose                  visual styles from the pop-up menu.
3. Choose                  one of the visual styles

Visual Style Examples

                     3D Hidden                                                               3D Wireframe

                          Conceptual                                                                           Realistic

Visual Aids

1. Click           the right mouse button while in the 3D Orbit command.

2. Choose       visual Aids from the pop-up menu.

3. Choose       Compass, Grid, or UCS Icon.

                           Compass                                                                           Grid

                                                                      UCS Icon

Free Orbit

1. Choose        View, Orbit, Free orbit

The 3D arc ball appears

2. Click          One of the 3D Orbit Arcball locations to move the display of your object(s).

Outside the Arcball - Moves View about                     Inside one of the small circles to the

an axis that extends through the center                      left/right - Rotates around the “Y” axis 

(acts like twist)                                                                 through the center.

  

Inside the Arcball - Allows movement in             Inside one of the small circles to the

any direction                                                               top/bottom - Rotates around the “X”

                                                                                        axis through the center.

Continuous Orbit

1. Choose        View, Orbit, Continuous orbit

2. Click            and drag to define the direction and speed of a continuous orbit for your object(s).

3. Press           ESC on the keyboard to stop the orbit.

Other Navigational Modes

1. Click             the right mouse button while in the 3D Orbit mode.

2. Choose        Other navigation modes from the pop-up menu

3. Choose        One of the following modes

Adjust distance(4)        Simulates moving the camera closer to the object or further way.

Swivel (5)                         Changes the cursor to an arched arrow and simulates the effect of                                                                     swivelling the camera.

Walk (6)                           Changes the cursor to a plus sign and enables you to "walk through"                                                                  a model at a fixed height above the XY plane, by dynamically                                                                              controlling the location and target of the camera.

Fly (7)                               Changes the cursor to a plus sign and enable you to "fly through" a                                                                    model without being restricted to a fixed height above the                                                                                   XY plane.

Zoom (8)                         Changes the cursor to a magnifying glass with plus (+) and minus (-)                                                               sign and simulates moving the camera closer to an object                                                                                 or farther away. Works like the Adjust Distance option.

Pan (9)                           Pans the drawing while in the 3D Oribit.

Animation Paths

1. Open             a drawing with 3D objects (Ex: sweep obj) and display in 3d view
2. Draw             a line or polyline representing a path for an animation
3. Choose         View, Motion Path Animation                                                                                                                            (or)
4. Type              ANIPATH at the command prompt                                                                                              Command: anipath
5. Select            path under the link camera to: option 
   
6. Click              the line or polyline path
7. Type              path1 as the default path name
8. Select            path under the link target to: Option 
   
9. Click             on the line or polyline path
10. Type             path2 as the default path name
11. Change        other animation settings such as the frames per second, duration, resolution, etc.,
    
12. Choose        the preview button to preview your animation
    
13. Close            the animation preview and click OK to create an animation file
    
14. Play              Your animation a pc or macintosh video review application such as Media player or quick time

3D Model Objects

(1) Wireframes

              A wireframe model is a skeletal description of a 3D object. There are no surfaces in a wireframe model; it consists only of points, lines, and curves that describe the edges of the object. With AutoCAD you can create wireframe models by positioning 2D objects anywhere in 3D space. AutoCAD also provides some 3D wireframe objects, such as 3D polylines (that can only have a CONTINUOUS line type ) and splines, Because each object that makes up a wireframe model must be independently drawn and positioned, this type of modeling can be the most time-consuming.

Wire frame lines in 3d view

(2)Surfaces

                   Surface modeling is more sophisticated than wireframe modeling in that it defines not only the edges of a 3D object, but also its surfaces. The AutoCAD surface modeler defines faceted surfaces using a polygonal mesh. Because the faces of the mesh are planar, the mesh can only appropriate curved surfaces.

 (3)Solids

              Solid modeling is the easiest type of 3D modeling to use. With the AutoCAD solid modeler, You can make 3D objects by creating basic 3D shapes; boxes, cones, cylinders, spheres, wedges, and tori (do nuts). You can then combine these shapes to create more complex solids by joining or subtracting them or finding their intersecting (over lapping) volume. You can also create solids by sweeping a 2D object along a path or revolving it about an axis.

2D Solid

Creates solid-filled triangles and quadrilaterals.

1. Type        SOLID at the command prompt

                    Command: solid

                    First point: P1

                    Second point: P2

                   Third point: P3

                   Fourth point: P4

                   Third point:  ENTER

3D Faces

           3DFACE creates a three or four sided surface anywhere in 3D space. You can specify different Z co-ordinates for each corner point of a 3D face. 3DFACE differes from SOLID, which creates a three or four sided surface that is parallel to the current UCS and can be extruded.

1. Begin        a new drawing

2. Set            the visual style to conceptual

3. Type        3DFACE at the command prompt

                    Command: 3dface

                     First point: Pick

                    Second point: Pick

                   Third point: Pick

                   Fourth point: Pick

                   Third point:  ENTER

3D Wireframe Lines                                   3D Face