Dec 13, 2005

Introduction to 3D Drawing

Ipek GurselOffice: A301igursel@yediyepe.edu.tr

Outline

3D drawing: Perspective Types Examples Assignment

A brief introduction to AutoCAD

Perspective: a definition... the technique of

representing three-dimensional objects and depth relationships on a two-dimensional surface.

may be used in paintings, architectural space representations, computer graphics, multimedia applications, computer games, etc.

types...1. paraline (orthographic)

isometric axonometric

2. conical

ISOMETRICthe angles between the projection of the x,

y, and z axes are all the same; 120°.

An example

PlanPlanFront viewFront viewSide viewSide view

An example

Plan Side view Front view

Lets draw a simple rectangle…

1. Lets draw the x, y and z axis.2. Measure off height, depth and length3. Draw your solid lines

10

5 3

5 103

A hands on exercise…

8

8

2 48

22

A brief introduction to: AUTOCADAUTOCAD

What is AutoCAD AutoCAD is a computer-aided drafting (CAD)

software package for 2D and 3D design and drafting, developed and sold by Autodesk. It currently runs exclusively on Microsoft operating systems. Versions for Unix and Mac were released (until R13), but these met with limited market acceptance and were later dropped.

Architects and engineers (AEC), drafters, cartographers, and other professionals involved with design

We have AutoCAD2006 installed in our machines

Some basics… 3d space: all objects are three dimensional in real life.

However, we cannot represent the third dimension on a 2d surface, such as a piece of paper or your monitors. So we use the Cartesian coordinate system on the 3d world of a CAD tool (remember your analytical geometry courses).

All the points in your space is defined by its x, y and z coordinates. In other words, AutoCAD uses points to determine where an object is located.

x

z

y

(6,4,0)

(2,1,0) x

y

(0,0,0)

(0,0,5)

(3,0,0)

(3,0,5)

(3,2,5)

UCS and WCS The AutoCAD world is 3 dimensional. However, if we want

to draw a 2d object, such as a plan or a section, we will use only 2 dimensions (x and y).

WCS (world coordinate system) is the imaginary plane that is parallel to the ground. It is the default coordinate system.

Modifications made to the World Coordinate System (WCS) result in a User Coordinate System (UCS). It is the plane that you work on. It enables the user to draw 3 dimensional objects.

To create a new UCS, type ucs on the command window, then say New and specify 3 points on your new UCS plane.

How do we give a command?

Command line Toolbars Drop-down menus

You can pick any one(s) that you are comfortable with.

Next week:

We will learcn to draw simple shapes, both 2D and 3D) with AutoCAD.

We will have hands-on exercises. This week’s assignment is due Thursday, March 9.

You will hand in the completed assignment sheets.