Next: Dimensioning Up: Basic Constructions and Previous: Trimming

### Area Generation (including Rectangle / Hatching)

SISCAD-P allows you to work very efficiently with areas. Generating areas should be preferred over generating elements.
The possible ways to generate areas are:

Figure 61: Area generation

Exercise (CREATE AREA AUT): Generate a polygon and hatch it.
Solution: The easiest way to generate a polygon is using DRAFT MODE. In order to be able to hatch the polygon, you must first promote it to area status. Use the command CREATE AREA AUT and position the point P inside the polygon. If the polygon was drawn without holes, SISCAD-P recognizes it and offers you the resulting area highlighted in color. If the polygon has holes, an area cannot be generated.

Figure: CREATE AREA AUT

To hatch the polygon, click the icons for the command CREATE HATCHING and select the area.

Figure: CREATE HATCHING

Exercise (CREATE AREA PLW resp. DIF): Generate an area with length= 90 and width= 50 at the co-ordinate origin, and another one with size L= 70, W= 30 at the point of co-ordinates (10,10).
From these two areas, you are to generate a rectangular shape that will be marked as alloyed steel.
Solution: Activate the icons for CREATE AREA PLW and enter the mandatory parameters for the point PNT, the length LEN and the width WID for both rectangles. You have now generated two areas, one inside the other.

Figure: CREATE AREA PLW

To obtain the required rectangular shape, you must generate the difference area between the two and the hatch it. Activate the command CREATE AREA DIF and then select for the mandatory parameters OPi first the large, and then the small area.

Figure: CREATE AREA DIF

To generate the hatching, activate the command CREATE HATCHING and select the difference area, that, if it has been correctly generated, is now highligted in color. Before you conclude the command, you must activate the optional parameter HPAT (hatch pattern), and select the desired hatch pattern among those that are on display.

Figure: CREATE HATCHING

Exercise (CREATE AREA BW resp. UNI): For this exercise, you will need the rectangular shape generated in the previous exercise, as well as another rectangle parallel to the co-ordinate axes with length= 60 and width= 20.
From these two items, create an area hatched with the pattern for plastics and with a hatch pattern spacing of 2 .
Solution: Generate a horizontal line segment of length 60 and activate the command CREATE AREA BW.
To create the required rectangle, you select this line segment, enter the width 20 and position your click point SEL below the line segment. The rectangle is displayed before the command completes.

Figure: CREATE AREA BW

To join the areas, use the command CREATE AREA UNI and select for parameters OPi first the rectangular shape, and then the rectangle.

Figure: CREATE AREA UNI

Now you must change the hatching of the new area using the command MODIFY HATCHING. Select the area and modify the hatching as required using the choice parameters HPAT and DST.

Figure: CREATE HATCHING

Next: Dimensioning Up: Basic Constructions and Previous: Trimming