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Complex hatch patterns can have an origin that passes through offsets from the origin and can have multiple members in the line family.
Not all hatch patterns use origin points of 0,0. Complex hatch patterns can have an origin that passes through offsets from the origin and can have multiple members in the line family. In composing more complex patterns, you need to carefully specify the starting point, offsets, and dash pattern of each line family to form the hatch pattern correctly.
The hatch pattern AR-B816 shown in the Boundary Hatch and Fill dialog box looks like this:
and is defined as follows with multiple lines describing the pattern:
*AR-B816, 8x16 Block elevation stretcher bond
0, 0,0, 0,8
90, 0,0, 8,8, 8,-8
The following figure illustrates a squared-off, inverted-U pattern (one line up, one over, and one down). The pattern repeats every one unit, and each unit is 0.5 high and wide.
This pattern would be defined as follows:
*IUS,Inverted U's
90, 0,0, 0,1, .5,-.5
0, 0,.5, 0,1, .5,-.5
270, .5,.5, 0,1, .5,-.5
The first line (the up bar) is a simple dashed line with 0,0 origin. The second line (the top bar) should begin at the end of the up bar, so its origin is 0,.5. The third line (the down bar) must start at the end of the top bar, which is at .5,.5 for the first instance of the pattern, so its origin is at this point. The third line of the pattern could be the following:
90, .5,0, 0,1, .5,-.5
270, .5,1, 0,1, -.5,.5
The dashed pattern starts at the origin points and continues in the vector direction given by the angle specification. Therefore, two dashed-line families that are opposed 180 degrees are not alike. Two solid-line families are alike.
The following pattern creates six-pointed stars.
This example can help you refine your skills at pattern definition. (Hint: 0.866 is the sine of 60 degrees.)
The following is the AutoCAD definition of this pattern:
*STARS,Star of David
0, 0,0, 0,.866, .5,-.5
60, 0,0, 0,.866, .5,-.5
120, .25,.433, 0,.866, .5,-.5