topic Re: Problem with SUBGROUP in GDL

Problem with SUBGROUP

Jim Allen — Fri, 24 Feb 2023 13:26:42 GMT

I'm building a parametric component for a modular battery storage unit. Everything works in terms of basic geometry creation, but I want to finish the component with some additional details - recessed handles and grooves.

This is what the 'dumb' component looks like:

This is the parametric one:

I need to undertake a subtraction to create the grooves and handles. I've created groups, and looked up the SUBGROUP syntax, but I'm getting an error.

This is my script:

"top": GROUP "topsection" ADDZ (footheight*2) + baseheight + modoffset +((modoffset + modheight)* modcopies) material mat2 !curved corner 1 ADDX footheight !footheight is same dimension as corner radius ADDY footheight CYLIND topheight, footheight del 2 !curved corner 2 ADDX A-footheight ADDY footheight CYLIND topheight, footheight del 2 !curved corner 3 ADDX footheight ADDY B-footheight CYLIND topheight, footheight del 2 !curved corner 4 ADDX A-footheight ADDY B-footheight CYLIND topheight, footheight del 2 SLAB 4, topheight, footheight, 0, 0, A-footheight,0, 0, A-footheight,B, 0, footheight, B, 0 SLAB 4, topheight, 0, footheight, 0, A, footheight, 0, A, B-footheight, 0, 0, B-footheight, 0 ENDGROUP GROUP "topgrooves" !groove1 material mat3 ADDX footheight SLAB 4, topheight, 0, 0, 0, GrooveWidth, 0, 0, GrooveWidth, GrooveDepth, 0, 0, GrooveDepth, 0 Del 1 !groove2 material mat3 ADDX A - GrooveWidth - footheight SLAB 4, topheight, 0, 0, 0, GrooveWidth, 0, 0, GrooveWidth, GrooveDepth, 0, 0, GrooveDepth, 0 Del 1 !groove3 material mat3 ADDX A - GrooveWidth - footheight ADDY B - GrooveDepth SLAB 4, topheight, 0, 0, 0, GrooveWidth, 0, 0, GrooveWidth, GrooveDepth, 0, 0, GrooveDepth, 0 Del 2 !groove4 material mat2 ADDX footheight ADDY B- GrooveDepth SLAB 4, topheight, 0, 0, 0, GrooveWidth, 0, 0, GrooveWidth, GrooveDepth, 0, 0, GrooveDepth, 0 Del 2 ENDGROUP topcomplete = SUBGROUP (topsection, topgrooves) del top RETURN

I've checked the syntax, but when I run the Check Script function, I get this error:

Group name or group type expression required at line 249 in the 3D script of file BYD Battery Box LVS.gsm.

I'm not sure what I'm doing wrong - any ideas?

Re: Problem with SUBGROUP

runxel — Mon, 20 Feb 2023 17:52:27 GMT

There are actually two types of groups.

Groups you have created with the GROUP command, which you will refer to with a string: "my group" (can have spaces)
Groups that result from a compound command, like SUBGROUP.

The result of the latter will be stored inside a variable – kind of like a function in other languages.

Funfact: VARTYPE will show type 2 for this variable (means string!), but you can not actually do string operations with this. Instead this works like a pointer to the resulting geometry stored in memory.

So check your SUBGROUP command: You use variables in error here, instead the names would need to be wrapped in quotes.
Happy coding!

Re: Problem with SUBGROUP

Jim Allen — Mon, 20 Feb 2023 18:09:18 GMT

Thanks, I've fixed the group definitions, and amended the SUBGROUP syntax, but it's not working.

There are no errors, and the geometry is displaying correctly - except the geometry subtraction.

This is the script:

"top": !ADDZ (footheight*2) + baseheight +((modoffset + modheight)* modcopies) ADDZ (footheight*2) + baseheight + modoffset +((modoffset + modheight)* modcopies) GROUP "topsection" material mat2 !curved corner 1 ADDX footheight !footheight is same dimension as corner radius ADDY footheight CYLIND topheight, footheight del 2 !curved corner 2 ADDX A-footheight ADDY footheight CYLIND topheight, footheight del 2 !curved corner 3 ADDX footheight ADDY B-footheight CYLIND topheight, footheight del 2 !curved corner 4 ADDX A-footheight ADDY B-footheight CYLIND topheight, footheight del 2 SLAB 4, topheight, footheight, 0, 0, A-footheight,0, 0, A-footheight,B, 0, footheight, B, 0 SLAB 4, topheight, 0, footheight, 0, A, footheight, 0, A, B-footheight, 0, 0, B-footheight, 0 ENDGROUP PLACEGROUP "topsection" GROUP "topgrooves" !groove1 ADDX footheight ADDY -nudge SLAB 4, topheight+(nudge*2), 0, 0, -nudge, GrooveWidth, 0, -nudge, GrooveWidth, GrooveDepth, -nudge, 0, GrooveDepth, -nudge Del 2 !groove2 ADDX A - GrooveWidth - footheight ADDY-nudge SLAB 4, topheight+(nudge*2), 0, 0, -nudge, GrooveWidth, 0, -nudge, GrooveWidth, GrooveDepth, -nudge, 0, GrooveDepth+nudge, -nudge Del 2 !groove3 ADDX A - GrooveWidth - footheight ADDY B - (GrooveDepth-nudge) SLAB 4, topheight+(nudge*2), 0, 0, -nudge, GrooveWidth, 0, -nudge, GrooveWidth, GrooveDepth, -nudge, 0, GrooveDepth, -nudge Del 2 !groove4 ADDX footheight ADDY B - (GrooveDepth-nudge) SLAB 4, topheight+(nudge*2), 0, 0, -nudge, GrooveWidth, 0, -nudge, GrooveWidth, GrooveDepth, -nudge, 0, GrooveDepth, -nudge Del 2 ENDGROUP PLACEGROUP "topgrooves" ! topsection = SUBGROUP ('topsection', 'topgrooves') PLACEGROUP "topsection" del top RETURN

I've adjusted the positions and dimensions of the cutting grooves so that they project through the target geometry, but there's no solid subtraction happening - unless I'm missing something.

This is the resulting object:

I'm doing something wrong, I'm just not sure exactly what...

Re: Problem with SUBGROUP

runxel — Mon, 20 Feb 2023 19:58:48 GMT

Now you've made the opposite error! Your last PLACEGROUP of course must not have the quotes 😉

If unsure: just reread my first post.

EDIT: Also I'm not sure why you place the group which is used for the subtraction. If you only did this temporarily for debugging, then it's fine.

Re: Problem with SUBGROUP

Jorge_Arreguin — Mon, 20 Feb 2023 20:21:32 GMT

check you last line must looks like it

topcomplete = SUBGROUP ("topsection", "topgrooves")

Re: Problem with SUBGROUP

AllanP — Tue, 21 Feb 2023 00:52:33 GMT

you may just want to just place the result of the subgroup...

placegroup subgroup("topsection","topgrooves")

remember to killgroup all groups at the end of the code.

killgroup "topsection"

killgroup "topgrooves"

"top": GROUP "topsection" ADDZ (footheight*2) + baseheight + modoffset +((modoffset + modheight)* modcopies) material mat2 !curved corner 1 ADDX footheight !footheight is same dimension as corner radius ADDY footheight CYLIND topheight, footheight del 2 !curved corner 2 ADDX A-footheight ADDY footheight CYLIND topheight, footheight del 2 !curved corner 3 ADDX footheight ADDY B-footheight CYLIND topheight, footheight del 2 !curved corner 4 ADDX A-footheight ADDY B-footheight CYLIND topheight, footheight del 2 SLAB 4, topheight, footheight, 0, 0, A-footheight,0, 0, A-footheight,B, 0, footheight, B, 0 SLAB 4, topheight, 0, footheight, 0, A, footheight, 0, A, B-footheight, 0, 0, B-footheight, 0 ENDGROUP GROUP "topgrooves" !groove1 material mat3 ADDX footheight SLAB 4, topheight, 0, 0, 0, GrooveWidth, 0, 0, GrooveWidth, GrooveDepth, 0, 0, GrooveDepth, 0 Del 1 !groove2 material mat3 ADDX A - GrooveWidth - footheight SLAB 4, topheight, 0, 0, 0, GrooveWidth, 0, 0, GrooveWidth, GrooveDepth, 0, 0, GrooveDepth, 0 Del 1 !groove3 material mat3 ADDX A - GrooveWidth - footheight ADDY B - GrooveDepth SLAB 4, topheight, 0, 0, 0, GrooveWidth, 0, 0, GrooveWidth, GrooveDepth, 0, 0, GrooveDepth, 0 Del 2 !groove4 material mat2 ADDX footheight ADDY B- GrooveDepth SLAB 4, topheight, 0, 0, 0, GrooveWidth, 0, 0, GrooveWidth, GrooveDepth, 0, 0, GrooveDepth, 0 Del 2 ENDGROUP placegroup SUBGROUP ("topsection", "topgrooves") killgroup "topsection" killgroup "topgrooves" del top RETURN

Re: Problem with SUBGROUP

Jim Allen — Tue, 21 Feb 2023 16:30:57 GMT

Thanks - I thought that the duplicate PLACEGROUP statements would create duplicate geometry, but the solid operation was not functioning, so when they were omitted, I had no geometry!

I got caught out by use of single and double quotes, and no quotes at all.

Re: Problem with SUBGROUP

Jim Allen — Tue, 21 Feb 2023 16:57:34 GMT

placegroup subgroup("topsection","topgrooves") doesn't work for me in AC25, I get this message:

Keywords can't be used as variables at line 229 in the 3D script of file BYD Battery Box LVS.gsm

Re: Problem with SUBGROUP

A_ Smith — Tue, 21 Feb 2023 17:10:44 GMT

then change your groups name. i guess "topsection" is a reserved word

Re: Problem with SUBGROUP

Barry Kelly — Wed, 22 Feb 2023 02:18:01 GMT

Try ...

topgroup = subgroup("topsection","topgrooves")

placegroup topgroup

Barry.

Re: Problem with SUBGROUP

Jim Allen — Wed, 22 Feb 2023 14:12:39 GMT

Thanks for everyone's help on this!

There are lots of subtleties in terms of where you use single quotes, where you can use double quotes, where you shouldn't use quotes, and the order in which you place commands including KILLGROUP.

The 3d elements and parameters of the object are complete:

I have the 2d view to script.

This is my first parametric object which can create alternative configurations of something.

I'll upload this to BIMComponents when it's complete, so I'm really grateful for everyone's generosity in terms of taking time to help.

I have a list of objects I want to build, including glass patch fittings, spur shelving, school coat hooks, cycle hoops and a half hexagon table.

Re: Problem with SUBGROUP

Barry Kelly — Thu, 23 Feb 2023 01:59:30 GMT

Single quotes ' or double quotes " - there is no real difference when creating a group name so long as they are used in pairs.

When you create a group the name must be in quotes i.e. GROUP "group_1".

If you place that group the name must also be in quotes.

Basically if it has quotes, every time you use that name it must be in quotes.

However, when you create a new group by merging 2 groups - i.e. newgroup = ADDGROUP("group_1", "group_2"), then that new group does not have quotes.

Now when ever you use that new group name, you do not need to use quotes.

It is a little confusing I agree, but is just the way GDL works.

Barry.