AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

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Valued Mentor
bcsurvey
Posts: 289
Registered: ‎04-29-2008
Message 1 of 6 (369 Views)
Accepted Solution

Inverse Point-to-Line??

369 Views, 5 Replies
07-30-2012 12:13 PM

In Land Desktop (a long long time ago) there was a routine whereby a surveyor could enter a set of points, then choose which points would be the endpoints of a line from which the offsets of other points would be shown.  In C3D 2012, the closest thing to this is in the Lines/Curve menu, Create Best Fit Entities, Create Line. 

 

But this allows only one point to be held, which I understand as it is "Best Fit" and not "Inverse". 

 

I just spent about 20 minutes bouncing around the internet looking for a way to do this.  If I can't find a way to do what I'd like, I'll have to either draw a line between two points and use that to inverse to each point, or make an alignment out of said line and use the Alignment Sta/OS option in the Inquiry menu.

 

Surely there's a way to do what I remember from the old days.  Software gets BETTER as it's further developed . . . right surveyors? . . . . . . . . . . . . . . . . . . 

 

Thanks

Civil 3D 2014
Windows 7 Professional SP1
Dell Precision T1700
(i7 @ 3.40 GHz)
8GB RAM
Nvidia Quadro K600

Apparently it IS possible to use the Lines/Curves menu, Best Fit Entity, Create Line to achieve what I'm thinking.  Although you can already pick one point and only one point to "Pass Through", you can also set the Weight value to as high a value as you want (I had thought that this had to be 1 or less).  So making the weight 1000000 for any point will give you an offset of 0.000 (most of the time).  So you'll basically have 2 points that the line is passing through.

 

 

Distinguished Contributor
MtnMax700
Posts: 141
Registered: ‎08-06-2010
Message 2 of 6 (367 Views)

Re: Inverse Point-to-Line??

07-30-2012 12:22 PM in reply to: bcsurvey

Civil 3D was NOT developed for surveyors.  Even Land Desktop left a lot to be desired compared to "COGO" software.

David

Valued Mentor
david.zavislan
Posts: 282
Registered: ‎10-31-2006
Message 3 of 6 (325 Views)

Re: Inverse Point-to-Line??

07-31-2012 08:59 AM in reply to: bcsurvey

If you want offsets relative to a line from pt1 to pt2, create an alignment between those two points. Then you can use inquiry tools or the reports manager (Stakeout Alignment Report) to generate station offset of the other points in the file.

 

If you don't want to mess with alignments, you can also do this with the Survey Command Window and its baseline commands:  BL IS will define the base line and BL INV will list points relative to the baseline.  The following image shows the Survey Command Window for a survey network named 'temp'.  The baseline is defined between points 1 and 2 with a starting station of 100.  Inverse data is listed for points 3 and 4.

SurveyCommandWindowBaseline.jpg

David Zavislan, P.E. | Wood Rodgers, Inc.
Active Contributor gk
Active Contributor
gk
Posts: 26
Registered: ‎12-06-2006
Message 4 of 6 (317 Views)

Re: Inverse Point-to-Line??

07-31-2012 09:46 AM in reply to: bcsurvey

Life would be so much easier if the survey commands were available for use with 'cogo points' instead of being available only for use with points which are in the survey database. So called 'cogo points' created in the drawing must be imported into the survey database to be able to use the survey commands on them. Points created in the drawing are called 'cogo points' but yet there are very few co-ordinate geometry routines available to use them with.

The idea of creating an alignment every time you want to check a perpendicular offset is absurd.

 

 

GarryK
Valued Mentor
bcsurvey
Posts: 289
Registered: ‎04-29-2008
Message 5 of 6 (310 Views)

Re: Inverse Point-to-Line??

07-31-2012 11:05 AM in reply to: bcsurvey

I've tinkered with this function for a bit and unless there is information other than what's found in the Help section on Survey Command Window, I am finding it extremely limited in what is can provide for surveyors.  I was going to reply to gk with a suggestion that he read the second half of your post describing the Survey Command Window, but after having gone through it, it seems that he already did. 

 

The BL IS command establishes a baseline with a station at the first point and BL INV allows a "range" of points to be analyzed for offset only .  That's fine, although having type in the command or even go into the menu and click in the boxes to enter points is a bit cumbersom.  The problems I have with the BL INV is that you cannot WEIGHT points more than others for a line regression, and you can only give a point RANGE, not a list of those points you want inversed.  The situation will arise readily for surveyors in which they have no interest in points within the lowest and highest numbers of those points they're analyzing.  For example, if I had a line of field-collected right-of-way monuments that I was trying to analyze and their numbers were 120, 125, 206, 212, 220, & 280, from what I know of the Survey Command Window at this point (which I'll admit may be insufficient), I'd be required to sort through all the points falling in between 120 and 280 in the results of the Survery Command Window.

 

I hope there is something I'm overlooking . . .

Civil 3D 2014
Windows 7 Professional SP1
Dell Precision T1700
(i7 @ 3.40 GHz)
8GB RAM
Nvidia Quadro K600
Valued Mentor
bcsurvey
Posts: 289
Registered: ‎04-29-2008
Message 6 of 6 (302 Views)

Re: Inverse Point-to-Line??

07-31-2012 11:34 AM in reply to: david.zavislan

Apparently it IS possible to use the Lines/Curves menu, Best Fit Entity, Create Line to achieve what I'm thinking.  Although you can already pick one point and only one point to "Pass Through", you can also set the Weight value to as high a value as you want (I had thought that this had to be 1 or less).  So making the weight 1000000 for any point will give you an offset of 0.000 (most of the time).  So you'll basically have 2 points that the line is passing through.

 

 

Civil 3D 2014
Windows 7 Professional SP1
Dell Precision T1700
(i7 @ 3.40 GHz)
8GB RAM
Nvidia Quadro K600
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