Topic: Fillet a polyline corner by corner...

[Peter2]

I have to fillet a polyline (LW and classic ..), but not in common (command fillet r 30 ...), but step by step:

- check the polyline
- check if the segments are to short for the defined radius R. Report problems
- fillet only corners and arc with r<R; arc with r>R stay unchanged

Do you know some code snippets to start with?

Thanks a regards

Peter

EDIT:
Link to the necessary (and many other) formulas - University Berlin, Geoinformatics and Survey:

http://public.beuth-hochschule.de/~korth/Formelsammlung_VK1.pdf

[tedg]

I have to fillet a polyline (LW and classic ..), but not in common (command fillet r 30 ...), but step by step:

- check the polyline
- check if the segments are to short for the defined radius R. Report problems
- fillet only corners and arc with r<R; arc with r>R stay unchanged

Do you know some code snippets to start with?

Thanks a regards

Peter

How is this different from the fillet command>polyline?
If the segment is too short it wont fillet it and returns

Code: [Select]


X lines were filleted
X were too short

I suppose that could be turned into a routine,

[Peter2]

Thanks tedg

but at the moment I don't see a way to solve it with the standard "fillet" commands. The current question is:

What's the background (the formula) of calculating a fillet of two lines?

[tedg]

Thanks tedg

but at the moment I don't see a way to solve it with the standard "fillet" commands. The current question is:

What's the background (the formula) of calculating a fillet of two lines?

Maybe I don't understand your process,
But your original post mentioned you want to fillet a pline with a defined radius, and if a segment is too short, to not have it fillet it.
And so that's what I was proposing, the fillet > polyline command does this and reports back what was filleted and what wasn't (if too short).


I have a simple lisp that this:

Code: [Select]


;;fillet polyline command that askes for radius first
(defun c:frp (/ rad pol fr)
(setq rad (getreal "Radius?")) (terpri);;<<-you define your desired radius
(setq pol (ssget))
(setq fr (getvar "filletrad"))
(setvar "filletrad" rad )
(command ".fillet" "p" pol)
(setvar "filletrad" fr)
(princ)
)

Hope it helps, or maybe you could explain more why you need something different.

[ChrisCarlson]

Are you asking for a method to perform the maximum fillet if it's less than the specified?

[BIGAL]

If you go to 1st principle and look at pline vertices then its simple to work out if radius is to big, likewise you can work out 2 new pick pts using two vertice points and the angle between them. If you want to just pick the corner check the vertices for that corner co-ords, then its a before and after pts, check also needed for closed or open as last point can be the same as 1st. Use vl-lisp 'get-cordinates.

[Peter2]

Thanks for all the postings.

In the meantime I made a solution with "analyse vertex - analyse segment before and behind - create the "fillet data" with a circle with TTR - analyse the circle, check if it correct to fillet - create new lists of coordinates and bulges".

It is a little bit tricky to check "what to fillet - what not - is it 'filletable' - ...., but at the moment this is my approach.

Have a fine day (rather warm here...)

Peter