Creating EG from Survey?

[travanx]

I was curious what the basic workflow is for creating an EG from a survey.  The catch is that we don't have a point file or elevated points on the drawing.  The drawing is just that a drawing with spot elevations and linework.  The lot is 100' long and 30' wide.  An existing house takes up most of the lot with a street on the front and back.  The idea is to try making a grading plan after I figure this first part out.  Where would I begin with something like this to figure out the next step of grading a small lot?

[Jay_B]

Do these points or lines have a Z elevation or are they 2d?

If they are 2d points do they have attributes representing the Z value for the  points?

[AllenJessup]

If all the elevation text for the spot elevation is the same distance from the point. You can use Move text to Elevation. Use the elevated text to create the surface. To get a good surface you'll need to create breaklines also.

You can do it even if they're not the same distance but then you have to move them individually. What you're looking for is to get the text insertion point to the place the elevation was taken.

Allen Jessup

[neilyj666]

there are several tools that will assign elevation values to points and work well if the text isnt too cluttered but can give mixed results if it is.

[Jeff_M]

And many shots can there be on a 100' x 30' lot covered mostly by an existing structure? It would take just a few minutes, at most, to manually add points at the locations needed.

[travanx]

The drawing is purely 2d with elevation text next to small circles.  But to build an existing surface I need to create more than points, I need breaklines as well.  Is this similar to using LDD?

[Jeff_M]

Similar, yes. Create the points, create the surface, add the Point Group with the points, add the breaklines, set the surface's style to the desired look. Again, on a site that small, this should not take more than a few minutes, start to finish, even for someone new to C3D.

[travanx]

I am used to making a breakline using a 3D polyline to connect the dots.  Say for the house or garage line.  Is that the same idea?  I was hoping to get the point file from the surveyor, but I figured this would be good practice when we can't get the point files for whatever reason.

[AllenJessup]

Create the breaklines by drawing Featurelines. Snap to the circle centers. Enter the elevation when prompted.

Allen Jessup

from my nook tablet

[jmayo-EE]

The best way to do this is to avoid it. If and when possible, ask the surveyor to provide you an xml file of the surface so you can remove this process of recreating their work. Many programs including LDD will create an xml file with ease.

[neilyj666]

I recently got the linework as well as an XML for an existing topo - the surface came in easily via XML and the linework was just used as an XREF for information eg location of walls,services etc etc - a very painless process

[gccdaemon]

Assuming you don't want to show all the point data try this.

1. Create a surface

2. Surface->Edit Surface->Add Point

This will allow you to pick points in the drawing and add elevations to those points without cluttering the drawing with point data.

Or, if you have topo lines, you can set them to their elevations using properties palette and add them to your surface as CONTOURS, not BREAKLINES. The weeding process is different between these entity types. all you'll have to do after that is go in and swap triangles using Surface->Edit Surface->Swap Edge.

Good luck, i hope this helps.

[jmayo-EE]

It is nice to get the deliverables that way Neil. Not always possible but when it is it saves a lot of time and guess work.

[neilyj666]

It certainly is but this was the eception rather than the rule unfortunately - we invariably get the data as described in this thread - text and 2d linework

[gccdaemon]

I blame Nicaragua, the metric system, and Bob Newhart for most of my frustrations....including this one. 

Edited by
Discussion_Admin

[travanx]

Thanks for everyone's help.  You wouldn't believe the way we sometimes get files and was curious how to manipulate a survey.  Let me add on this particular site the siteplan is hand drafted.  The reason I chose this specific survey is that the surveyor can get me the points file.  But they haven't responded to my request yet.  We also have other sites where the developer is no longer talking to the surveyor so no more getting extra anything beyond the 2d line and text survey.  I was trying to figure out even if I was to redraw a survey, would the grading be faster to do in C3D.