arc start & end pts & normal in vba

it seems that regardless of which way an arc is drawn in autocad (CW, CCW), vba alway lists the start pt & end pt as if it was drawn CCW (which ends up being the opposite of what it should be 50% fo the time). is this correct?
also i checked the normal for 2 arcs, 1 drawn CW, the other CCW, both were 0,0,1. it seems that 1 should 0,0, 1, & the the other should be 0,0, -1 (based on the right hand rule)?

 

I just did a quick test and it looks like VBA is not your problem. I drew
the same arc twice, CW and then CCW, and when I listed them in ACAD, they
had the same start angle and the same end angle. So it looks like ACAD
forgets which way you drew the arc as soon as you draw it. BTW, if you draw
an arc that completes the circle of a previous arc, their Start and End
angles will be swapped.

HTH,
James

CCW), vba alway lists the start pt & end pt as if it was drawn CCW (which
ends up being the opposite of what it should be 50% fo the time). is this
correct?

0,0,1. it seems that 1 should 0,0, 1, & the the other should be 0,0, -1
(based on the right hand rule)?

 

ok thanks.
hmmmm.
well thats interesting.

i'm doing a curved polyline to straightsegment polyline conversion kindof thing. it only works half the time, depending on which way the curves are drawn.
by using pedit, edit i can trace the order the new pl was drawn, when it doesn't come out right, all the points after the first are backwards, i know why this is happening (i think), but can't find a test for it, because ACAD can't keep it straight.

ARGHHHHHHHHHHHHHH!

(& now i think the time spend on this can never be made up in any effencies gained by using this routine throught the rest of my working life (if i ever get it to work))

 

Post your routine if you can. Someone will be able to figure out a quick
solution, I think. I didn't know you were looking at polyline arc segments,
I just looked at a regular arc.

As far as time goes, this routine may not pay for itself, but you also have
knowledge from creating it that you'll be able to apply to future problems.

The sign of the .GetBulge value for an arc segment may help you figure out
which direction that segment goes.

HTH,
James

thing. it only works half the time, depending on which way the curves are
drawn.

doesn't come out right, all the points after the first are backwards, i know
why this is happening (i think), but can't find a test for it, because ACAD
can't keep it straight.

effencies gained by using this routine throught the rest of my working life
(if i ever get it to work))

 

Arcs in AutoCAD are always stored with a CCW start/end. Been that way since
the beginning.
--
John Goodfellow
irtfnm
use john at goodfellowassoc dot com

CCW), vba alway lists the start pt & end pt as if it was drawn CCW (which
ends up being the opposite of what it should be 50% fo the time). is this
correct?

0,0,1. it seems that 1 should 0,0, 1, & the the other should be 0,0, -1
(based on the right hand rule)?

 

all i needed to do was use the get buldge method on the original polyline to figure out which way the individual arcs are going