topic Re: Object with nested opening for slabs in GDL

Object with nested opening for slabs

jc4d — Wed, 05 Oct 2022 07:03:42 GMT

Hello,

I have to create a chimney in gdl, the tricky part is that in the section drawings the hole has to be shown in the slabs. Therefore, I was thinking on using the opening tool to cut the slabs, but I would like to avoid placing 2 separate objects (chimney and opening).

Is there a way to achieve it with a gdl object?

Juan

Re: Object with nested opening for slabs

Barry Kelly — Wed, 05 Oct 2022 07:31:03 GMT

I don't think you can call an opening into an object.

But it is possible to script a PRISM_ where you want the hole to be cut in the floor.

Obviously the chimney is hollow inside so a Solid Element Operation with subtraction from the slab will only remove the solid walls of the chimney.

You then contain the PRISM_ for the hole in a command that only activates when you perform an SEO.

Something like this that I use all the time for my vanity basins ....

!GLOB_CONTEXT = 44 !! use prism to cut bowls when used in Solid Element Operation if GLOB_CONTEXT > 40 and GLOB_CONTEXT < 50 then ADDz 0 for i=1 to 32 PUT cos(i*11.25)*0.220,sin(i*11.25)*0.220,15-2 next i PRISM_ 32, 0.200, GET(NSP) DEL 1 endif

This will cut an oval shaped hole but you can substitute a rectangular PRISM_.

Just uncomment the first line to see the prism in the object preview as you script.

Make the prism the same size and height as the void in the chimney and you won't have to worry about figuring out floor heights.

Basically what you will be doing is creating a solid centre to the chimney that will only activate when an SEO is performed.

Just a simple 'Subtraction' with the slabs as the targets and the chimney object as the operator.

Barry.

Re: Object with nested opening for slabs

jc4d — Wed, 05 Oct 2022 07:42:14 GMT

Thank you, so I have to rely on SEO operations then?

Re: Object with nested opening for slabs

Barry Kelly — Wed, 05 Oct 2022 08:00:41 GMT

That is the only way I can think to semi-automate it.

Otherwise it is use a separate un-associated opening as you had thought of before.

Barry.

Re: Object with nested opening for slabs

jc4d — Wed, 05 Oct 2022 08:10:30 GMT

Ouch, this workarounds could be avoided is skylights could be used on slabs as well.

I will have to ask the archictects what workflow they would prefer.

The idea behind this question is that when designing a building with more than 10k m2 and having n amount to chimneys, keeping track of SEO operations it would become a real nightmare. But yeah, your tip worked as expected 🙂

I did try by selecting a simple generated block and use the opening tool with the magic wand, to get size from the block and place a opening with those dimensions, but didn't work. 🤔

You wrote this (sorry quoting selected text desn't work):
"I don't think you can call an opening into an object"

So, what about calling an object into an opening?

Juan.

Re: Object with nested opening for slabs

DGSketcher — Wed, 05 Oct 2022 08:17:02 GMT

@jc4d Depending on the detail of your chimney, have you considered using a Complex Profile with a Column to create the chimney rather than GDL? If the column uses stronger materials it should automatically intersect and form the required opening in the slab.

Re: Object with nested opening for slabs

jc4d — Wed, 05 Oct 2022 08:57:29 GMT

Great tip, thank you.

The details are kind of high. If I could call a wall, column or a beam (thank you for the link to the chart), would be great since the hole is a basic rectangular shape but not the object itself.