Topic: Daunting Task (Terramodel -> Civil3D Construction Staking)

[surveyor_randy]

Ok, where do I start....

I am in charge of converting our entire survey department from Terramodel to Civil3D.  I am looking for some pointers and suggestions from other surveyors who are using C3D for construction staking.  The design work is damn easy in C3D but it doesn't seem as friendly to us surveyors as LDD was.

C3D is points galore when working with pipes, alignments, etc, HOWEVER, they are not COGO points so they are useless to us for staking purposes.  Why the distinction?  Terramodel considers a point as a point!  Shouldn't every point that has an X,Y,Z be considered a COGO point.

Basically, I am asking, how do you offset lines and maintain their elevations?  I found another thread regarding a similar topic but it evolved into a VBA and lisp routine discussion.

Terramodel worked fine for what we were doing but the people upstairs (engineers) decided that we now need to be using C3D.  Help!! 

[surveyor_randy]

PS - it is p*ss poor design from Autodesk to allow points everywhere for engineers to do their design work but keep us surveyors from using them. 

[sinc]

Basically, I am asking, how do you offset lines and maintain their elevations?  I found another thread regarding a similar topic but it evolved into a VBA and lisp routine discussion.

Not quite sure I follow you here...  Maybe you are looking for Grading->Edit Feature Lines->Stepped Offset?  This works for Feature Lines, Survey Figures, and 3D-Polylines.  Just beware that Autodesk broke it in 2008 SP2, and the offset line loses all elevation points that are not also horizontal PIs.

Unfortunately, you will discover that C3D is not very surveyor-friendly.  Autodesk largely has no concept at all of what surveyors do or how they work.  Most of their efforts so far have been devoted to the Equipment Database (which is completely useless, since this issue is handled already by the data collectors), and the Survey Database (largely useless, because it doesn't understand GPS, among other issues).  They do not understand boundary work at all, or construction calcs, or field data collection, and C3D is woefully inadequate for all of these.  They don't even have a good grasp on State Plane vs. Ground coordinates, or US Survey Feet vs. International Feet, both of which are implemented improperly in C3D.  They've been getting a lot of feedback on these issues, among others, and we're hoping that the 2009 release will provide some relief, but right now, C3D is pretty limited in its survey support.

That being said, we would not even consider using Land Desktop at this point.  C3D is flawed, but still far better than that ancient program.  But the only thing that's made C3D usable for us at this point are the routines found in the SincpacC3D (a free download).

The STAKEFEATURES routine in that set of utilities creates offset points to feature lines.  Calc'ing 3' offsets to the TBC around parking lots with that routine is MUCH nicer than it was in Land Desktop.  Turn your TBC into a feature line, grade the feature line from the spot elevations in the plans, and then run STAKEFEATURES to calc all stakeout points all at once.

[surveyor_randy]

Unfortunately, you will discover that C3D is not very surveyor-friendly.  Autodesk largely has no concept at all of what surveyors do or how they work.  Most of their efforts so far have been devoted to the Equipment Database (which is completely useless, since this issue is handled already by the data collectors), and the Survey Database (largely useless, because it doesn't understand GPS, among other issues).

You obviously are a surveyor yourself!  I don't even bother with the 'Survey database' portion of C3D.  We just create a polyline boundary and adjust it.  All of the BS of entering data about your instrument is quite insignificant.  And the survey database is useless, other then being able to lock points.

I am interested in knowing how other surveyors are creating COGO points from completed designs.  How are you guys creating points for data collectors from sewer systems, water lines, storm drains, etc.  I really wish that Autodesk would realize that EVERY point that has an X,Y,Z is a POINT.  There should be no distinction between a COGO point and any other point.  How are we expected to implement the design?  My contractor is wanting the sewer system staked at 25' offsets and we have no problem doing this with Terramodel.  But with C3D, everything becomes a learning adventure for us.

[Dinosaur]

Yes, sinc has managed to assemble a very helpful set of tools for using Civil 3D for surveying related functions.  JeffM, another member here, has also shared some valuable tools. They are definitely worth your time to download all of them.
I am curious what version of Civil 3D you are working with; the 2008 version has changed some of the ways it deals with points and may solve some of your questions although the points functionality has been one of the more friendly parts of the program.  I am also unfamiliar with Terramodel and what you might need to get from Civil 3D to make it do what you need, but I have had no problems creating stakeout points for our surveyors.  Do you need to export points out of the drawing in a format not listed as a choice?

[surveyor_randy]

Thanks for the suggestion, we are using C3D 2008 SP2 and I have downloaded the SincPac but haven't really played with it yet.  In terramodel, to stake a sewer line for example, the procedure was quite easy.  We offset the sewerline 25' first.  Then set the out elevation at one end of the line and the in elevation at the other end.  Then, if we want points at 25' increments, we just trim the line by 25' and it creates a point at the proper elevation based on the slope from the start point to the end point.  We then repeat this process and it creates another point.  In terramodel, you can trim a line by typing a distance and clicking on the line multiple times (it's quite fast).  It intuitively knows that you want to trim from the closest endpoint.  Even though the portion of the line segment disappears after you've trimmed the line, the point still exists. 

I am working on a vba routine that will offset a line or polyline with a 3D-polyline, then set the Z values based on the Z values of the vertices of the 3D polyline.  If the original object that was offset was a line/polyline, then it will prompt the user for Z values.  It would also give the user the option to reverse the line.  Then finally, create COGO points from those vertice points.  It isn't too much of a task to create this routine but I am quite surprised that C3D 2008 wouldn't have a similar routine built into it.  Or at least, an easier way to offset a line with elevations at intervals for staking purposes.

We export coordinates into an ASCII file PNEZD (comma) to load into our data collectors.

[surveyor_randy]

Another routine I am considering writing:

It would sort of associate COGO points with an object.  Meaning, if I grabbed a line, polygon, etc and moved it or rotated it, it would make the proper adjustment to the associated COGO points along that particular object, meaning, points created along the line or perimeter of the polygon.  I know that this is possible with a selection set but it would be nice to just click anywhere along the object and have the object and the associated COGO points added to the selection set.  I think it would be pretty easy to write a routine that would run along the perimeter and grab any COGO points it encounters along the way.

[Dinosaur]

Thank you for the explanation.  I think that you should be able to create the points you require quite easily as long as you are making your offsets along an alignment or create an alignment along your offset line.  On the POINTS pulldown, you will find a flyout for Create Points - Alignment that will give you several methods of automatic point creation.
The way I deal with these points for export is to have a point style and a label style set up for staking points along with their own layer that is specified in the styles.  I make a point group set up for these points and populate it with only these points and also include my control point group that I have set up in a similar manner.  The point group may not populate as expected until you update the point group manually in Toolspace.  A point export to file of points within this group definition using your preferred format should return exactly what you need.
This is just a rough explanation assuming you know some of your way around Civil 3D and it's interface.  I will be happy to clarify anything you still need help with.

[mjfarrell]

Stephen and Sinc,  I have to say there are times that you guys really make a teacher proud, and humble at the same time.   Keep the good work!

[sinc]

Another routine I am considering writing:

It would sort of associate COGO points with an object.  Meaning, if I grabbed a line, polygon, etc and moved it or rotated it, it would make the proper adjustment to the associated COGO points along that particular object, meaning, points created along the line or perimeter of the polygon.  I know that this is possible with a selection set but it would be nice to just click anywhere along the object and have the object and the associated COGO points added to the selection set.  I think it would be pretty easy to write a routine that would run along the perimeter and grab any COGO points it encounters along the way.

I don't think it's that simple.  If it just "grabbed" any point it found, it might grab the wrong points.

I've been thinking of trying to extend the STAKEFEATURES command so that the points all auto-update if the featureline is edited, but it isn't a simple task.  It should be possible, but it will take a bit of work, and I've been busy with more-pressing tasks first.

[sinc]

In terramodel, to stake a sewer line for example, the procedure was quite easy.  We offset the sewerline 25' first.  Then set the out elevation at one end of the line and the in elevation at the other end.  Then, if we want points at 25' increments, we just trim the line by 25' and it creates a point at the proper elevation based on the slope from the start point to the end point.  We then repeat this process and it creates another point.

[...]

We export coordinates into an ASCII file PNEZD (comma) to load into our data collectors.

I think you might want to check into exporting Alignments and Profiles to your data collector instead.  That's what we do for our utilities.  Then the field guys can use the station/offset stakeout feature in their data collectors to stake out offsets at any point along the utility line, at any offset.

If you use Trimble equipment, get the Trimble Link from Trimble's website.  This lets you simply select Alignments in C3D and dump them straight into your data collector.  The whole process is very painless, and much simpler than generating a lot of points.

[sinc]

Stephen and Sinc,  I have to say there are times that you guys really make a teacher proud, and humble at the same time.   Keep the good work!

You?  Humble?         

[Dinosaur]

I don't think it's that simple.  If it just "grabbed" any point it found, it might grab the wrong points.

I've been thinking of trying to extend the STAKEFEATURES command so that the points all auto-update if the featureline is edited, but it isn't a simple task.  It should be possible, but it will take a bit of work, and I've been busy with more-pressing tasks first.

Sinc, with 2008 allowing us to select individual points finally, would there be a way to use them within a regular AutoCAD group and manipulate them in this fashion along with the other associated objects?

[surveyor_randy]

I think you might want to check into exporting Alignments and Profiles to your data collector instead.  That's what we do for our utilities.  Then the field guys can use the station/offset stakeout feature in their data collectors to stake out offsets at any point along the utility line, at any offset.

That seems like a good idea, but doesn't it slow the guys down in the field instead of them having a drawing with point numbers and points already created in the data collector?  BTW - nice job on sincpac and thanks for keeping it free and sharing your source code! 

[surveyor_randy]

Thank you for the explanation.  I think that you should be able to create the points you require quite easily as long as you are making your offsets along an alignment or create an alignment along your offset line.  On the POINTS pulldown, you will find a flyout for Create Points - Alignment that will give you several methods of automatic point creation.

I like this idea too.  If I offset a line, then create an alignment on my offset.  How do I assign start and end elevations for the Alignment?  This is where I start to get confused.  This website is great and I'm glad that I found it.  Actually, Sinc's website pointed me here!