Civil3D surface data to GIS

[watersam]

I do a lot of hydraulic modeling and create river bed surface datafrom surveyed points.  I need to be able to transfer the surface data from Civil3D to GIS effectively.  The issue is that GIS does not maintain the fidelity of my surface based on the breaklines I've drawn.  It triangulates based on vertices and often triangulates through the feature lines.  In LDD, I was able to do address this by adding vertices to my 3D polylines in a batch-type function.  That is, I could select all of my 3D polylines and add vertices to them at the same time.  In Civil3D, I have to add vertices to each feature line individually. 

Does anyone know of a way to add vertices to feature lines, or to a surface, in a more efficient manner that maintains fidelity of surface data in the transfer from Civil3D to GIS?

Thanks,

Sam

[Matt.Anderson]

Have you looked into Project River Analysis for your River Hydraulic Modeling?  

On your original questions - you could always "smooth" your surface, and then reproject your breaklines onto the surface to add additional verticies.

[neilyj666 · Accepted solution]

Can you export the triangles (I'm not particularly familiar with GIS but this is a fairly foolproof way of maintaining the fidelity of the surface)

[watersam]

I'll look into this....

[watersam]

Thanks, but GIS still only looks at the triangle vertices and doesn't understand the breaklines.  I might have come up with a work-around though.  I exported the triangles as a polygon shapefile, then converted it to a polyline shape and then used the ETGeowizards tools in GIS to densify the polylines to a 1' vertex spacing so that GIS will hopefully have difficulty interpolating through the triangle sides.  This seems to have given satisfactory results and is not too lengthy a process.

[neilyj666]

Check out the AU class from 2010 CV231-1 Slope stability analysis wih Civil 3d by Donal McMoreland where he extracts surfaces to GIS (I'm working through it at the moment) that may help you a bit. I'm no GIS guru so don't know whether it will or not

[Matt.Anderson]

Sam -

What type of GIS analysis are you preparing?

btw - Project River Analysis is a free download here: http://labs.autodesk.com/utilities/civil3d_river/

[Murph_Map]

What type of GIS program, E$SRI is only one there are many out there that work as well or better that handle DEM/TIN data differently.

[watersam]

Matt,

Thanks again for the modeling info.  I'm not doing much of an analysis in GIS.  Simply getting my surface data for the channel of a river pasted into a monster LiDAR surface and then exporting those points to a 2D hydraulic model.  GIS handles the large point files better and it's the platform that everyone else in my office uses.  In addition, point export functions in GIS seem to have more options for adjusting density.  I did try using a point cloud to make a LiDAR surface and that worked OK, but in this case there are more heavy surfaces that are involved that are already processed in GIS, so it makes sense for me to transfer the TIN to GIS.  Also, the surface created in the 2D model will bear more resemblance to the GIS surface in terms of how it triangulates data, so viewing and manipulating surfaces in GIS prior to incorporating in a model makes sense.

-Sam

[ericcollins6932]

Breaklines can be added to the surface in GIS - you'll just have to bring them in.

http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=Breaklines%20in%20surface%20modeling

[watersam]

thanks, Eric.  It's the "bringing them in" that I'm trying to figure out.  If you know of a way to bring C3D feature lines directly into GIS as a polylineZM shapefile, please let me know!  That would solve all my problems.  I could densify my 3D lines in GIS, make the tin in GIS and avoid all the conversions.

-Sam

[Matt.Anderson]

Sam -

Thanks.  So, within ESRI, you are using XPSWMM or MIKE for the 2D simulation?  River Analysis is a just HEC-RAS, or 1D simulation tool. 

Why the 2D hydraulic simulation? Regulatory?

 sorry for the inquisition...

[Matt.Anderson]

Murph -

No, I assume its that base program.  I am more interested in the Hydraulic analysis that he is attempting to perform once he gets the surface TIN.

As he explained:

LiDAR data set -> processed into GIS

Surveyd channel -> Civil 3D -> export via subject of original post -> push into GIS

Final surface in GIS so that XYZ program can read it and perform 2D hydraulic riverine flooding analysis.

so, I am after XYZ...

[ericcollins6932]

featurelines are civil objects and ESRI can't handle objects. Export to Autocad 2007 I think will convert/explode your feature lines to polylines? Then you could just add the .dwg as a layer and export them to a shapefile.

If the export to acad 2007 doesn't do it, you can always convert feature lines to polylines, and then bring them into esri.

[watersam]

Matt and Murph,

Sorry for holding out on you....I'm using ArcGIS--that's what I've got and I don't think that's going to change.  The 2D hydraulic model I'll be using could be any number of models, depending on the client.  Typically, we'll use MIKE21, SRH2D, River2D, and we're going to be getting another model soon.  I'm not sure which one this surface will go into, but I think it'll be MIKE, as there will be several types of analyses done.  We use 2D models because we focus on habitat, natural processes, etc., and 2D simply gives a much more detailed explanation of the hydraulics.

As for my original question, I think a recent poster just answered my question.  I'll export the feature lines to a previous version.  2000 is best for creating shapefiles in ArcGIS, in my experience.  I'll make a polyline shapefile out of the exploded feature lines (they come in as fragments of lines, at elevation once saved back) and densify the polylines until they're approaching a string of points.  That oughta do it.  So thanks for that post, and I apologize for not acknowledging your name, I just can't see it on my current page.

-Sam

[watersam · Accepted solution]

Thanks, Eric!  That's the solution I've been looking for for some time now.

-Sam

[Murph_Map]

---

@watersam wrote:

As for my original question, I think a recent poster just answered my question.  I'll export the feature lines to a previous version.  2000 is best for creating shapefiles in ArcGIS, in my experience.  I'll make a polyline shapefile out of the exploded feature lines (they come in as fragments of lines, at elevation once saved back) and densify the polylines until they're approaching a string of points.  That oughta do it.  So thanks for that post, and I apologize for not acknowledging your name, I just can't see it on my current page.

-Sam

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When you export 3d plines with the Map export command to an E$RI shp format, on the option tab click on driver options and select 3D shape files, this should create the zpoly feature type.

[ericcollins6932]

Murph's elegant solution vs my brute force one - I love it.

Am stealing Murph's solution for my tricks CASE document...

CASE = copy and steal everything...

[wdbar]

I'm curious if you guys ever run into situations where you use LiDAR info to suppliment an on the ground topo survey.  If so, how do you handle the scaling coversion from Grid to Local?  Do you covert in ESRI and build Civil 3D surfaces after ESRI transposes it?

I've built several surfaces from GIS files in C3D over a large developement and the scale difference is very glaring.  Ny first instinct is to scale the surface entity to local.  But I'm wondering if I should be creating contours and scaling the extracted polylines and rebuilding the surface from the scaled polylines.

[wfberry]

Covert?  Are you kidding?

Seriously, what you are doing is commonly referred as hi-jacking an existing thread.  Please start a new one with the approproate title.

Thanks,

Bill