Voids in GDL

[Ingolf]

I want to make a Block in GDL with an internal hole, the object made in the simplest possible way. Of course I can make four walls and a roof and make a Block with a hole that way, but I want to make two Blocks, one regular and one smaller void-Block. Is there a command for void in GDL?

[Barry Kelly]

It can also be done with a BLOCK and a CUTPOLYA.

The depth of the CUTPOLYA can be limited so it is not infinite.

Just a matter of positioning it and rotating if necessary.

A little harder to work with as you can't see it unless it is cutting something.

Barry

[Ingolf]

Pointing me in that direction, I managed to create a Block with a hole 😊 But I do not know how to make the hole finite, so that there will be a "roof" in the Block. I tried with this script:

Material 4

a=1.0
d=0.2

GOSUB "rect_cut"
DEL 1

BLOCK a, a, a
CUTEND


END
"rect_cut":
    CUTPOLY 4,
            d, d,
            a-d, d,
            a-d, a-d,
            d, a-d
    RETURN

Any suggestions? 

[Barry Kelly]

CUTPOLYA is a half infinite tube from the x-y plane, and you can set the length of that tube (0 is infinite length).

You can also mask the edges of the cut as you would mask the edges of a PRISM.

Barry.