topic Re: Voids in GDL in GDL

Voids in GDL

Ingolf — Thu, 26 Sep 2024 11:48:49 GMT

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?

Re: Voids in GDL

runxel — Mon, 23 Oct 2023 21:02:07 GMT

Yes, that's possible. You should look in to the SUBGROUP command.

Re: Voids in GDL

Ingolf — Mon, 23 Oct 2023 21:06:59 GMT

Thanks for a swift answer. I suspected the Subgroup. But how to script a Block and a void with Subgroup?

Re: Voids in GDL

DGSketcher — Mon, 23 Oct 2023 21:20:40 GMT

Here's a couple of links you might like to explore...

https://gdl.graphisoft.com/gdl-basics/advanced-3d-components

https://gdl.graphisoft.com/reference-guide/solid-geometry-commands

Re: Voids in GDL

Barry Kelly — Tue, 24 Oct 2023 01:17:09 GMT

BLOCK and BRICK can not have a hole directly scripted in them.

You can use GROUPs as others have suggested and SUBGROUP one from the other.

Not hard, but you need to know how the grouping works.

I would just use the PRISM_ command (or its variations.

PRISM_ 10, 1.0, 0.0, 0.0, 15, 1.0, 0.0, 15, 1.0, 1.0, 15, 0.0, 1.0, 15, 0.0, 0.0, -1, 0.2, 0.2, 15, 0.8, 0.2, 15, 0.8, 0.8, 15, 0.2, 0.8, 15, 0.2, 0.2, -1

The -1 mask means the following nodes will cut a hole.

Barry.

Re: Voids in GDL

Ingolf — Tue, 24 Oct 2023 06:18:36 GMT

Thank you Barry. But: I need a script where the hole does not cut all the way through the cube. That will probably not be possible in your otherwise elegant solution?

Re: Voids in GDL

Barry Kelly — Tue, 24 Oct 2023 06:30:39 GMT

Ah, you want a hollow block with 6 sides still?

You could add slabs (prisms) to the top and bottom to plug the hole.

But easy with GROUPs.

GROUP "box" BLOCK 1, 1, 1 ENDGROUP GROUP "void" ADD 0.2, 0.2, 0.2 BLOCK 0.6, 0.6, 0.6 DEL 1 ENDGROUP result = SUBGROUP ("box","void") PLACEGROUP result

This is the wire frame view.

Barry.

Re: Voids in GDL

Ingolf — Tue, 24 Oct 2023 06:31:16 GMT

Hello DGSketcher

The link https://gdl.graphisoft.com/gdl-basics/advanced-3d-components will probably help me on track. Thank you 🙂

Re: Voids in GDL

Ingolf — Tue, 24 Oct 2023 06:53:38 GMT

That worked well, and not a too complex formula. I changed it so I could see the void from the botom 🙂

Material 4

GROUP "box"

BLOCK 1, 1, 1

ENDGROUP

GROUP "void"

ADD 0.2, 0.2, 0

BLOCK 0.6, 0.6, 0.6

DEL 1

ENDGROUP

result = SUBGROUP ("box","void")

PLACEGROUP result

How did you do the list (with the GDL-script) in your answer? How did you place the list in a grey box with a slider? 🤔

Re: Voids in GDL

Barry Kelly — Tue, 24 Oct 2023 07:07:03 GMT

Expand the editing tool bar (3 dots) at the top where you type your reply.

That will create the code box.

Barry.

Re: Voids in GDL

Barry Kelly — Tue, 24 Oct 2023 07:14:32 GMT

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

Re: Voids in GDL

Ingolf — Tue, 24 Oct 2023 13:00:23 GMT

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?

Re: Voids in GDL

Barry Kelly — Wed, 25 Oct 2023 01:38:23 GMT

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.