Isaland detection bpoly autocad function

outland86 · 3 Jan 2010, 04:44

Hello all

there is a little known fuction in autocad called bpoly and it works like this .it is basically an island detection and seperation function here is some info on it

BPOLY command description:
Creates a boundary polyline
Use the bpoly command.after using this command, a dialog box opens and you have to pick a point inside the closed area.Please note that this works only for "closed" areas.
A polygon is formed at the boundary of closed area.
you can now erase the original entities and use the closed polygon thus formed.

If you have several segments in a drawing that you want to extract and you want to make closed polygons, that you can seperate away as pieces see the drawing attached and think i would want to click inside any part of this drawing and it would create a copy of the boundry polyline that would then offset itself as a clone that i could move aside
in this manner i could make up seperate parts of the drawing that could be a puzzle that could be put back together to create the original drawing. these puzzles could be made very quickly using a script to automate all or much of the island detected polyline copys.
could a plugin be written ? if so very large and complex puzzles could be made very quickly which is what i am hoping for can anyone solve this problem and is it possible to write this sort of plugin?

i have attached a drawing to show what i mean about drawing that needs to be broken simply into parts

thanks for reading

thomthom · 3 Jan 2010, 11:51

Can't you just use the faces that the edges split?

Or is it imported from another program and there are no faces? In that case, would it not be enough to intersect the edges and run the Make Faces script?

outland86 · 3 Jan 2010, 16:32

hello

i am not a pro with sketchup so please bear with me
the files i want to use are imported from another cad program as DXF files if you imagine
a pattern and you want to be able to break it apart in to its parts so you can cut them on a CNC machine but the original DXF is made up of layers and not islands as in the drawing so if you select the polylines you dont get actual parts i hope i am not sounding too confusing here .
you need to be able to seperate the parts to be able to cut them indervidually with a CNC machine and put them, back together later.
i can do this with autocad but i want to get a sketchup system happening to do some of my ideas so that everyone can make cool projetcs that can be cut on Robotic tools without having to spend a ton of money on high end Cad Cam software so i have many plugin tools in mind for sketchup and developiong your milling tools plugin would be one way that could cover that but i think it would be a big job so i have perhaps a way to help compensate you for this effort if are you interested in working with me ? or anyone else out there
that might be interested and has the right skills please email me info<at>makecnc<dot>com

thanks

Paul Campbell
http://www.makecnc.com
http://www.fabscity.com

Join the Revolution !

JClements · 3 Jan 2010, 16:32

Assuming all lines are coplanar, select all and do an intersection?

thomthom · 3 Jan 2010, 17:04

Do you have an example file?

The thing is though - is SU really the best tool with CNC machines? I'm thinking in regards to curves - as SU doesn't have true curves - instead faceted. You can change the segments of arcs and circles in SU - but when you import DWG and DXF files you never get the option to set the number of segments so in some cases you end up with noticeable segmentation.

TIG · 3 Jan 2010, 17:30

If you 'face' all of the required areas and make sure everything is intersected, so no loose edges: then I already wrote a plugin to make selected faces into components... http://forums.sketchucation.com/viewtopic.php?p=186068#p186068 ...

thomthom · 3 Jan 2010, 18:17

And once you've made groups/components of each piece, you can use this plugin to space them apart from each other: http://forums.sketchucation.com/viewtopic.php?f=323&t=24390

pilou · 3 Jan 2010, 18:30

@unknownuser said:

And once you've made groups/components of each piece, you can use this plugin to space them apart from each other: viewtopic.php?f=323&t=24390

Damned it's my script (and c.plassais)

outland86 · 3 Jan 2010, 20:12

hi and thanks for all your interest in this subject
the point of all this Milling tools plugin stuff is so that i can create several step by step simple process for people to design certain types of products.FABS
they need to be able to do this very simply with minnmal sketchup experiance.
this will help people who are stuck at home make some extra income online making real products.

the reason i have chosen SU is that it is free for them to dwonload and learn and is well supported and hopefully will continue to be. if they take to the subject they can move on to more well suited CADCAM software as they make money from thier designs.
so simple easy to use methods need to be developed that are mostly a few clicks only to achieve the results. this bpoly command needs to be scripted in such a way that it can detect all faces inside a given area if the user clicks inside that area.say one of the areas in the picture i posted above then the next click produces a clone of that shape and moves it aside by a given amount where the user can after erasing the master export those single parts as DXF file

some of these projetcs can get very complex having hundreds of parts so a quick easy way is essential to the sucess of such a method. i dont know if this is beyond the scope of SU as a program you all would be able to tell me that.
you are right about arcs being better than segments for CNC but is it possible for SU to have plugin that replaces the segments in a drawing with arcs? or perhaps a simple external program could take care of this problem when sending the file to the CAM program for the toolpaths.
again this is one of several methods i would like to see created that could open up the world of FABS creation to everyone the dogbones plugin is a great step in the right direction but a single script that handled several of the most comon proceses would be ground breaking stuff and help make the FABS revolution happen
my two cents
thanks

put the world back to work ! in a green way

Join the Evolution !
http://www.fabscity.com

pilou · 3 Jan 2010, 23:31

@unknownuser said:

select all and do an intersection?

@unknownuser said:

would it not be enough to intersect the edges and run the Make Faces script?

It's not sufficient!

You must (assuming there are not surfaces, only coplanar edges)
Select all
Intersect Selected
Select all
Make face
Select each face + its edges, (double click)
Make a group else you can't move the piece's puzzle
et voila
I suppose exist a plug that make a group with some different faces + edges selected?
If not that is the task

thomthom · 4 Jan 2010, 09:30

Moved this topic to the Developer section of the forum.

outland86 · 18 Jan 2010, 23:30

did everyone just give up on this ?