How Autocad Coordinate system works?
Let’s little bit talk about Autocad coordinate system. Coordinate system one of the fundamental thing that you need to understand. The coordinate system is actually in every CAD software that’s why to try to understand it clearly.
Most of the time you’ll not use a coordinate system in your work. Of course, if you are not working in an area where you need to use it. But sometimes coordinates very useful.
Let’s begin to learn the coordinate system and we will begin from WCS (World coordinate system). The coordinate system inside Autocad similar to real World coordinates system.
WCS is a rectangular system that starts from the certain point with coordinates 0, 0 that located in left bottom corner of Autocad. Every created object has characteristic points with assigned coordinates. These points responsible for the position of the object in model space relative to the origin of WCS.
The defining points of primitives
Line – first point and last point
Polyline and polygons – Top point
Circle, arc, and spiral – center point.
There are three types of coordinates
- Absolute coordinates
- Relative coordinates
- Polar coordinates
How to draw object with Absolute coordinates
Let’s see how to draw objects with absolute coordinates.
1.Call Line command
2. Autocad will ask Specify first point, Enter X (10) and Y (10) coordinates and press Enter.
3. After first point is specified enter line length and angle.
How to draw object in AutoCAD with relative coordinates
How relative coordinates works?
Relative coordinates take last drawn object endpoint as point 0. You need to just enter @ front of a coordinate into the field. Let me explain to you how it works.
Above you draw a line with absolute coordinates (10,10).
- After you finish drawing activate Line command.
- Autocad again will ask you Specify first point.
- Before you will enter coordinates enter @
- Then again enter X – 15 and Y – 20 and press Enter on the keyboard.
In image below, you’ll see how it will look like
How polar coordinates work in Autocad
By default positive value of angle rolling counterclockwise, that is negative clockwise.
Here is an example.
In the example, you can see a line with Length 8 units and it’s 225 rotated concerning positive X-axis.
Starting point built with absolute coordinates -2, -2.
To draw endpoint you need to enter 8<225 into command line
8 – line length
< – angle symbol
225 – angle which is necessary to turn the line.
In this tutorial, you learn basic parameters of Autocad coordinate system. In future lessons, you will continue to learn Autocad coordinate system to understand Autocad deeper.