Any idea how to place line with known length by middle point? Be it v8i or CE.
Like simple example here, draw a cross by two lines from middle symmetric to center. Line length from center is known but angle can be arbitrary. Yes cells can be placed, scaled and rotated but it is not line.
I can't think of anything, since a line is defined at its most basic, from a start point and an end point. The center point doesn't exist until the start and end points have been established, and even then "center point" is more of a property of begin/end point than a defining feature of the line.
I'll admit, it has been a LONG time since my high school geometry class. I'll be interested in what others might suggest.
MaryB
Power GeoPak 08.11.09.918Power InRoads 08.11.09.918OpenRoads Designer 2021 R2
Hi Oto,
I think it's not possible. The closest tool is classic old Place line, allowing to preset both length and angle. But no midpoint as placement can be set.
On the other hand, to create such tool in VBA or C# should be quite simple, because it's "a line only" ;-)
A question is exact workflow, especially how rotation is expected to be define (by value or by 2nd point?).
With regards,
Jan
Bentley Accredited Developer: iTwin Platform - AssociateLabyrinth Technology | dev.notes() | cad.point
I agree with Jan that its not achievable with default out-of-the-box tools however it is certainly achievable with VBA:
Simple 3-4-5 triangle test case. I noticed using the tool that there is a little bit of noticeable lag with the dynamics that you don't get with regular MS Tools e.g. Place Line tool. I'm unsure if its a performance issue due to this being a VBA solution (and not C++ which I believe the standard commands are written in) or perhaps my approach is causing it (which is entirely feasible as I haven't coded any VBA for quite a while and I had to use some partial code found in previous topics). Jan and Jon will likely be able to advise a more elegant solution (perhaps using methods which I am not familiar with) however mine does appear to work perfectly well from the limited testing I did. I've added some comments within the _DataPoint event to explain my approach, the rest is pretty much just the Line creation example from the help file and the GetActiveAngleFrom2Points function was written previously by Artur Goldsweer.
LineFromCentre.mvba
Thanks this is almost what was expecting. Only would like to provide length as input before and just mark the angle.
To give more background attaching example. The need is to mark pavement blocks 4m wide but as the sides are not so clear it is easier to mark by center.
place-line-challenge.dgn