Hi all! I need a big help 
I need lisp to detect non tangent arcs in polyline, and then fillet segments before and after it with same radius as that arc. Is it possible?
I found program to detect non tangent arcs so i can edit it manually, but it would be cool if it can be done automatically
Thanx in advance!
(I have polylines that are made using fillet command, but now its slightly changed/moved, so i need to do fillet again.)
(sorry for bad english, its not my native language)
@Anonymous wrote:
....
I need lisp to detect non tangent arcs in polyline, and then fillet segments before and after it with same radius as that arc. Is it possible?
....(I have polylines that are made using fillet command, but now its slightly changed/moved, so i need to do fillet again.)
....
Welcome to these Forums!
Can you provide a sample drawing or image showing the kinds of changes you may need to re-Fillet for?
Many such changes I can imagine would result in an arc segment with a different radius from the original, so if you re-Fillet the corner matching the current arc-segment radius, it will be different from what you started with. Is that what you want? For example, this one I altered by dragging the arc segment's midpoint grip outboard slightly:
But at a right-angle corner like that, with adjacent line segments not altered, it should be possible to calculate what the original corner radius was, and restore that.
Or are you talking about arc segments that are not changed, and all changes happening to adjacent line segments?
@john.uhden wrote:
I am guessing that he would want to refillet the tangents with an arc of the same radius, so the tangent points would shift along their straight segments. ....
But.... The "same radius" as what? Here's another possible kind of change -- the left one is the original, the right one has had its right edge Stretched farther to the right.
Re-Filleting that right one with the same radius as its arc segment currently has would not be the same as doing so with the original radius, just as in my previous Reply. [It might not even be possible, depending on the lengths of adjacent line segments.] But I can't imagine a way to calculate what that original radius was, unless you can be sure of certain things about the nature of the change that has been made. For example, in this case, if you know that a right-angle corner like this may have been stretched thus in a direction parallel to one of the line segments, and will have had only one edge altered in that way, the original radius could be calculated. But being able to count on such limited possibilities doesn't seem likely.
And what would they want to do with something like this?
That's why I asked what kinds of changes might occur. Some kinds could probably be handled, but some kinds would be very difficult, if not impossible, to know what to do with.
@john.uhden wrote:
.... When the polyline was originally filleted, the drafter applied a chosen radius. It ain't that hard to apply the same desired radius programmatically. ....
Applying it isn't very hard. It's determining what it was, from information contained in a Polyline where it has been altered, that could be utterly impossible, again depending on the exact nature of the change(s) that may have been made. Applying the same radius to all corners of a Polyline is easy enough with the Polyline option in Fillet as @dbroad suggested, but that would not be appropriate if a Polyline they want to fix may have originally had different radii on different corners, or some corners Filleted and some not, etc., etc.
@Anonymous wrote:
I found this program that do what i want just manually (you need to click on arc to get radius and then on segments to fillet), so i was hoping that there is way to do this by clicking on polyline.
.....
Does that not work with picking on an un-altered arc segment of the Polyline for the radius, and then choosing the Polyline option and picking the Polyline, if you want to re-Fillet all its corners? It takes two User inputs to the Fillet command, which can be two segments, but can instead be a P and the selection of the Polyline.
Or if it does work that way, is that not what you want to do? If your idea is to simply pick a Polyline once, if it's been altered, it probably has arc segments of different radii, so how is a routine to know which one to use? And if it would use the Polyline option in Fillet, would your Polylines ever have non-radiused corners that you would want to keep that way? Fillet's Polyline option won't leave those alone.
Here is my somewhat more sophisticated routine to do the same kind of thing, with extras like *error* handling, etc., and this difference: instead of doing a Fillet command and allowing two-and-only-two pauses for User input, and then ending, it puts you in a whatever-you-need Fillet command, in which you can choose the Polyline option to re-Fillet an entire Polyline or pick segments [and only those you want rounded corners between, in case there are some where you don't], and even keep going and do as many of them as you want at the same radius.
