Display full version of the post: Truncating poylines (help please!)

wuhanmatt
17.05.2013, 11:03

Hi,I would really like to be able to truncate the length of a polyline, I don't think its possible, but I thought I would ask anyway, because I am an optimist I would like to draw numerous polylines from a point on a file, lets say lines that denote distances from an exit or some other feature of a building floor plan. For each exit there will be numerous lines going along each route to a distance of (lets say) approximately 100 m.This would result in multiple poly-lines (or perimeter measurements) all leading from a single point and all having a similar, but not exactly the same, length. Is it possible to then truncate these lines so that they are all (lets say) 90 m in length, so that the last ~10 m is cut off. And then do it again to 80 m, and then to 70, etc etc.I would effectively want to "anchor" one end of a polytime to a point, in this case a door. I would then want to specify the length of the polyline such that the end (and not the anchored point) is truncated.If I could do this it would be a great help. I cant think of another way of doing what i want. It could be done with circles of known radius however due the internal layout this is not accurate enough.Regards,Matt

philippe JOSEPH
17.05.2013, 11:41
Hello Wuhanmatt,I use AutoCAD Mechanical 2012 and I can modify the length of a polyline with the command TRIM.
Do prefer using the command TRIM instead of modifying the length with the help of the grips because sometimes you will modify the geometry of the polyline.
Maybe you can also use parametric constraints to do this if it exists on your TurboCAD.
What release of AutoCAD are you using : 2010 , 2012 etc...

wuhanmatt
17.05.2013, 11:58

Hi Joseph, Thanks for your reply. Trim sounds like what i would want to do! Can you do it to multiple lines at the same time? Does it only owrk in the mechanical version? I think i'm using autocad 2012, but i would have to check (its on my work computer, i'm at home now). I dont use cad very often. I never have to produce outputs in CAD, and i sometimes need to use a cad file as an input to my work - but normaly i use a pdf instead. so i'm a bit of a newbie at this, but i have a working knowledge of cad. Regards, Matt

philippe JOSEPH
17.05.2013, 13:33
Hello again Matt, you can TRIM multiple lines with the option T ( like Trajet on my french release ) and with 2 ( or + ) you define the lines that you want to trim.
Lauch the command TRIM, select the line ( or lines ) on wich you want the others lines to be trimmed,
type T ( for "trajet" or it will be an other word ) and trim what you want.
I did some searches and it looks like the option is F like fence.
Maybe some other guy ( or you can check this ).
Ask for more.
P.S. on your screen, you should have at least the 3 tool bars : Drawing, Modification and Dimension for a minimum efficiency.

philippe JOSEPH
17.05.2013, 13:44

 
See the TIP N° 3361 right here in the site : how to trim multiple lines at an edge with one command?

Kent Cooper
17.05.2013, 15:10
LENGTHEN with the Total option.  Pick the end you want changed, rather than the end you want to stay where it is.