Page 1 of 1

how do I create offset hatches

Posted: Thu Mar 04, 2010 4:40 pm
by LeoP
In cross sections where the section plane is folded, it is some times necessary to indicate the location of this fold line by shifting the hatch pattern by half the pitch on either side (standard NEN-ISO-128-40).

How do I do that in QCAD Professional, short of drawing every single line of the hatch?

Posted: Thu Mar 04, 2010 10:25 pm
by andrew
I'm not sure I understand your question.

For any shape of hatch, you will have to create the exact hatch boundary first, then hatch it. Note that the hatch boundary might be placed on an separate layer, so it can be easily hidden if desired.

If you need full control over every single line of a hatch, you might want to explode it after creation. This splits the hatch up into line segments: Modify - Explode.

Posted: Fri Mar 05, 2010 12:09 am
by LeoP
I know it sounds a bit weird (when done right, it looks great though).

What I some times need is a way to hatch two adjacent shapes with the same pattern, while the hatch lines do not continue from one shape to the next. Even when I hatch these two shapes separately, it still looks like the hatch is made from one (the combined) shape.

Exploding the hatch after creating does not solve the problem: I would then need to delete every other line in both hatches... I have no 'externally accessible' storage space, otherwise I could show exactly what is needed in a little drawing.

Posted: Fri Mar 05, 2010 9:11 am
by andrew
I think I understand now. There is no offset parameter for hatch patterns. However, you can most likely solve the problem with a separate hatch pattern in which the lines have the same angle but different positions than in the original hatch:


The hatch pattern at the left is "ansi31" (included with QCAD), the one at the right "ansi31b" (new). You can download ansi31b from here:

Save it into the "patterns" directory of QCAD, then restart QCAD to start using the new pattern.

Posted: Fri Mar 05, 2010 10:49 am
by LeoP
Spot on! :D
According to NEN-ISO-128-40, the vertical separation line would have to be omitted, but that's trivial.
I'll have a look into pattern design, but use your supplied one for now.