We are quite familiar with line and circle, which are common concepts in our daily life, CAD has introduced polyline, which means a line consisting of multiple lines and (or) arcs. Polyline consisting of multiple lines and arcs is drawn and edited as a whole, making it very convenient to use.
If we don’t customize the setup options, polyline would look exactly like lines and both of them could be used continuously. Then is there a way to help us tell polyline from line?
If we use the same method to draw three continuous lines and polyline, we’ll find the difference when we point select them: although the three lines are continuous, they are three independent objects while polyline of three segments is regarded as one object, as shown in the following picture.
We can also see the difference in their icons. Polyline consists of not only line but also arc, that’s why polyline has more parameters than line. Let’s see how to draw a polyline.
1.Click polyline button (as shown in the following picture) or enter PL then press Enter to start Polyline command.
2. Specify a point in the graphics window as the first point of the polyline, press F8 to open “Ortho Mode”, move the cursor upward some distance, enter “20” and press Enter to complete the drawing, as shown in the following picture.
In many cases we need to draw in the horizontal or vertical direction, CAD has provided ortho mode in which the cursor movement is constrained to the horizontal or vertical direction. We can switch Ortho Mode on or off either by F8 or by clicking on the button, as shown in the following picture.
We have talked about how to draw with coordinates, actually, there is another way: use the cursor to specify the direction and then enter the length.
3. Move the cursor to the left, enter 65, draw the second line, as shown in the following picture,
In the following steps, we are going to complete drawing arc.
1.Enter A, press Enter to activate the Arc command. As you can see in the drop-down menu shown in the following picture, there are many ways to draw an arc.
Here we choose to draw an arc with radius.
2. When prompted to specify the radius, enter 20, press Enter, move the cursor downward, enter 40 to complete the arc.
Enter L to activate Line command, move the cursor to the right, enter 65, press Enter, enter C, press Enter to make the polyline closed, as shown in the following picture.
Polyline has many parameters in common with lines as well as many unique parameters such as width and half-width. In this post, we have gone through steps of drawing polyline and more practices are highly recommended to every beginner to know the most commonly used parameters including their function and position.