CAD (intro)

CAD

Computer-aided design

INDEX

Coordinates

Coordinate systems

Navy Wars

CAD

Let's draw

Excercises

01

Coordinates

To a computer a drawing is just a collection of points. Each point is defined by two numbers: the coordinates.

Coordinates

My ships

Opponent's ships

Navy Wars

How do we play?

01

02

03

Absolute cartesian coordinates

Relative cartesian coordinates

Relative polar coordinates

Coordinate systems

Absolute cartesian coordinate

Absolute coordinates refers to a Cartesian System that uses x-axis (horizontal) and y-axis (vertical) to establish a point some distance from a common origin. A point is defined by two values X and Y and we write them as: X,Y. Use absolute coordinates when you know the precise X and Y values of the point. For example, the picture's origin point is (0,0) and the absolute coordinate defining the rectangle are (1,1), (5,1), (5,3) and (1,3).

Coordinate systems

Relative cartesian coordinate

Use relative coordinates when you know the location of a point in relation to the previous point. To specify relative coordinates, precede the coordinate values with an @ sign (@X,Y).For example, we start with a point at (1,1) and we want to move 4 mm to the right so we write @4,0. Then, we want to go 2 mm up and we write @0,2. Finally, if we want to go to the left 4 mm we should write @-4,0. Question: How can we go down?

Coordinate systems

Relative Polar coordinate

You can use absolute or relative polar coordinates (distance and angle) to locate points when creating objects. To use polar coordinates to specify a point, enter a distance and an angle separated by an angle bracket (<): @d<α For example, entering @1<45 specifies a point at a distance of 1 unit from the last point specified at an angle of 45 degrees from the X axis. You can see at the picure how we define our rectangle.

Coordinate systems

Let's draw

Let's draw

Let's draw

Let's draw

Excercise 2

Excercise 2

Excercise 2

Excercise 2

Thanks!