How to use Bpoly function?

[nguyennhattanpt]

I'm researching the Bpoly function but haven't found any documentation on how to use this function. Hope anyone can explain to me. I've been doing a little research now.
(bpoly [point] [selection-set] [option-keyword] ...)
option-keyword as a list but I don't know how to use it.
Help me!

Thank.

[komondormrex]

i think the only parameter in the bpoly function is a point. if it finds a closed boundary at a given point, then it draws a polyline boundary and returns its ename; otherwise, it returns nil.

[Kent1Cooper]

It's odd that (bpoly) is not in the AutoLisp Reference.  But it does exist as an AutoLisp function, and @komondormrex seems to be correct [one trial here] that a single point argument does it.  For more complex situations, you should of course be able to use the BPOLY command rather than the AutoLisp function.

[nguyennhattanpt]

Not really. bpoly function allows the use of 0, 1 or more variables. If there is no variable, it will be like a command boundary. 1 variable works as you said.
i used with 3 variables it worked. variable 2 is Selection-set ; same as boundary-set of the boundary statement.
3rd variable is a list (I tried with '(0 0 0)); I don't understand what it is.
The msg returned is: "Invalid option keyword"

[nguyennhattanpt]

Try using this command: (bpoly (getpoint) (ssget) '(0 0 0))

you will see it working!

[komondormrex]

mmmm, this has no sense, i mean for (bpoly) to have parameters other than a point. i mean, i think it is a short-function method apart from the command to get pline boundary at a point. but who knows... 

[Kent1Cooper]

Without some documentation of the arguments and syntax required [I haven't found any], who can say?  So I have to ask:  where or how did you encounter (bpoly) as an AutoLisp function rather than a command, and where do you get the idea of the arguments you suggest?

[ВeekeeCZ · Accepted solution]

best I could find.

https://www.theswamp.org/index.php?topic=24759.0

[pkenewell6347]

Example Post Link : HERE

Simple usage: 

(setq e (bpoly (getpoint)))

FYI - It is currently not recommended to use this undocumented function because it has some issues. Instead you should use:

(setq bp (getpoint "\nSelect Internal Point: "))

(command "._-Boundary" "_non" bp "")
; Get new polyline created
(setq en (entlast))

[nguyennhattanpt]

Tkank BeekeecCZ.
At the end of the conference the error still appears, I also have the same error and cannot resolve it.

[Sea-Haven]

Used bpoly for years, inside lisps or manual, I think you need to post a dwg so we can see what it is your trying to do. If its lisp post code as well.

[nguyennhattanpt]

I usually use (command "_.boundary" ...) however recently I discovered there is a function (bpoly pt), assuming this function will run directly without going through cmd; So I want to learn to improve Autolisp's running speed

[pkenewell6347]

Have you tried to use it via my last post? It does work and is simple. There are no other options or setup to use. The function - at least for now - is loaded by AutoCAD at startup.

Please again note however that this is an undocumented, unsupported function, so there is very little documentation on it's usage at all. Try searching for it in Autodesk's help in the product documentation or the developer's guide and it is non-existent.

If someone can correct me on this - Show me where the documentation exists because I would love to know as well. I think it is an ADS function written in C? Have they updated it?

[Sea-Haven]

 (bpoly pt) not supported in Bricscad V20 maybe a later version. But help says exists.