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Civil 3D and Ground Distances

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(@scott-in-indianapolis)
Posts: 222
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Topic starter
 

I want a way to specify (1) the effective combined scale factor for a drawing and (2) rotation (difference between deed and grid/SPC cords). Then I can use an expression to apply these "variables" to label lines (make a line label style) based on ground distances and deed bearings. This allows us to survey in SPC, draft in SPC, go back to the field in SPC, design in SPC (no jobs larger than 350' square), turn stuff into the local GIS department (%$*!) in SPC, etc.

The problem is that I don't want CAD guys to have to dig through the expression editor for each job. I would rather them enter these two "variables" in the dwgprops/field editor with the other info (job #, job name, county, twshp., sec-twn-range, draftsman initials, etc.). These variables would be given to them. The expression editor would then just pull the values from the field value.

It doesn't seem this is possible because it doesn't seem that expressions recognize field values.

Is this correct? Is there a work around? Other methods? Ideas? How do you handle this?

Scott B.

 
Posted : November 22, 2016 7:04 am
(@mark-mayer)
Posts: 3368
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It seems that you have this thing thought through much more than I do. I was simply hoping for a way to apply convergence angle to the line labels.

 
Posted : November 22, 2016 7:36 am
(@sek-surveyor)
Posts: 37
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I have been using an expression to label ground distances on a grid drawing. The expression has to be modified for each drawing. I have not found a better way yet, but am waiting to see what responses you get from others.

DR

 
Posted : November 22, 2016 11:25 am
(@wa-id-surveyor)
Posts: 932
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Sounds like a tricky setup. While we only have 1 municipality in our area that requires a GIS type deliverable we always send them our data and supply the Grid Scale Factor and let them figure it out. We cannot efficiently work on grid. Too many ground related moving parts to keep the data secure.

We tried variations of what you described above through setting the grid scale factor in the survey database and in the point export setups. We did complete one fairly large project this way but quickly abandoned that setup due to the inherent difficulties in keeping things straight. Now we always work on ground with all data being exported from TBC on ground.

 
Posted : November 22, 2016 12:38 pm
squirl
(@squirl)
Posts: 1190
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There isn't a variable for this. My suggestion would be for you to create TEMPLATES for the most commonly used situations. I'm not sure this answers your general question but TEMPLATES are the way to go if you're having to repeat steps, multiple times.

T. Nelson - SAM

 
Posted : November 22, 2016 12:50 pm

(@david-livingstone)
Posts: 1124
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sek-surveyor, post: 400680, member: 6157 wrote: I have been using an expression to label ground distances on a grid drawing. The expression has to be modified for each drawing. I have not found a better way yet, but am waiting to see what responses you get from others.

DR

This is the way I do it, I only mess with the distances and leave the all the bearings on grid.

 
Posted : November 22, 2016 3:36 pm
(@joe-the-surveyor)
Posts: 1948
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Mostly off topic with this, but just as an FYI, C3D usually defaults to international foot and not survey foot. Which can drive you nuts, and cause potential problems if you work in SPC.

 
Posted : November 22, 2016 4:27 pm
Jim in AZ
(@jim-in-az)
Posts: 3364
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Joe the Surveyor, post: 400729, member: 118 wrote: Mostly off topic with this, but just as an FYI, C3D usually defaults to international foot and not survey foot. Which can drive you nuts, and cause potential problems if you work in SPC.

Not here in Arizona :)!

 
Posted : November 22, 2016 4:50 pm
not-my-real-name
(@not-my-real-name)
Posts: 1076
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Does Civil 3D have Transformation Settings like Land Desk Top (LDT)? I would make a transformation and then use the geodetic labels. Geodetic labels can be set to display various items like convergence angle at a location or grid and ground distances on a line. I use this method with LDT. I am sure that Civil 3D must have the same functionality.

Historic boundaries and conservation efforts.

 
Posted : November 23, 2016 5:53 am
squirl
(@squirl)
Posts: 1190
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Joe the Surveyor, post: 400729, member: 118 wrote: Mostly off topic with this, but just as an FYI, C3D usually defaults to international foot and not survey foot. Which can drive you nuts, and cause potential problems if you work in SPC.

Another good reason to use a template.

T. Nelson - SAM

 
Posted : November 23, 2016 5:55 am

(@scott-in-indianapolis)
Posts: 222
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Topic starter
 

Squireltech - I am kind of a freak about drafting/CADD (yes there are two D's in CADD 🙂 ) standards - therefore templates are important to me. I don't see templates working here since every survey job where matching a deed bearing is important will be different. So as far as rotation goes, the template elements controlling rotation will be different.

 
Posted : November 23, 2016 7:17 am
(@scott-in-indianapolis)
Posts: 222
Member
Topic starter
 

Yes - Civil 3D has transformation settings, but it doesn't quite work for rotation. I'll try to explain to the best of my ability:
1. C3D's geodetic bearing is based on the transformed coordinate. That is to say, the transformed two coordinates pairs (points) of a line.
2. Projected (transformed) points on a line segment will have more distortion the longer it is and the further it is from the reference plane (SPC or ellipsoid).
3. Therefore, the amount of rotation (distortion) from the grid will vary (slightly, 1"-2") with line length.

What I want is a CONSTANT rotation. Why? Because this is what the deed reflects. I am trying to match the deed for boundary survey plat preparation. Why is the deed rotation constant? Because the survey that it was originally based upon was performed with a compass/theodolite/total station measuring horizontal angles without the same account for earth curvature that we are employing today.

The transformation settings are functional, however.

 
Posted : November 23, 2016 7:32 am
(@scott-in-indianapolis)
Posts: 222
Member
Topic starter
 

I am just looking for a standard (Template, Squirltech!) that I can employ for all surveys to account for surveying and drafting on SPC with no transformations, but we can label ground distances and bearings. This is what the public will see and relate to when they read a survey plat. Last point - the survey should typically match the deed unless there is cause to update it.

Thanks for all your input - it seems that expressions are still the best way to go.

 
Posted : November 23, 2016 7:40 am
(@wa-id-surveyor)
Posts: 932
Member
 

not my real name, post: 400772, member: 8199 wrote: Does Civil 3D have Transformation Settings like Land Desk Top (LDT)? I would make a transformation and then use the geodetic labels. Geodetic labels can be set to display various items like convergence angle at a location or grid and ground distances on a line. I use this method with LDT. I am sure that Civil 3D must have the same functionality.

Yes it does.

 
Posted : November 23, 2016 7:53 am
(@wa-id-surveyor)
Posts: 932
Member
 

Joe the Surveyor, post: 400729, member: 118 wrote: Mostly off topic with this, but just as an FYI, C3D usually defaults to international foot and not survey foot. Which can drive you nuts, and cause potential problems if you work in SPC.

As Squril identified...use templates and this is a complete non-issue.

 
Posted : November 23, 2016 7:54 am