Existing Conditions from Survey data workflows

[Anonymous]

Subject:

I read a post other week that has me questioning some of our current practices for creating existing conditions from survey data.  I wanted to get the communities feed back on some of your processes. 

Current State:

Currently we are using survey databases, survey figures, and imported points to create line work, for planimetrics and breaklines, and surfaces in a single drawing. As such all our line work is 3D and all the survey points reside in the drawing.

Problem:

As we all know points can significantly slow down a drawing even if they are filtered to not display and sometimes even when frozen.  Secondly, our designers prefer 2D line work for some things because it makes it easier to offset and hatch things.  Thirdly, we do have a desire to have the DTM in a seperate drawing from the line work simply for file management reasons and i have seen posts where this seems to be a common practice.

Question:

1.  How does one create a drawing with just a DTM if the 3d objects needed for it to be created are not in the same drawing.

2.  Even if we can create this it feels like alot of extra work because I am thinking it takes like 3 drawings to represent everything we want.  One with everything in it, line work and surface, all 3D.  Two, maybe datashort cut then promote the surface from the combined to have a drawing with only DTM.  Three, save as the 3d drawing, then explode survey figures, remove points, and flattern.  Thats a lot of work!

[jefflambert9091]

We have a surface drawing that keeps the survey figures intact for a "field" surface and then we create a datashortcut. We then have the main drawing where we flatten all survey figures for drafting and datashortcut in the surface. Our civil's do all their grading in C3D. Civil's and myself included do not like survey figures. They are great for field to finish and to get the linework in and get a surface. On the larger jobs (+4000 points) we may even get rid of some of the field points (we leave that up to the civil do decide), but everything is always in the surface drawing and in the survey database.  See this thread https://forums.autodesk.com/t5/civil-3d-forum/survey-figures-amp-2d-vs-3d-drawings/m-p/9346072

[Anonymous]

So similar to our current workflow.  Thx for input.

[LucasHicks · Accepted solution]

I think I've found an easy way to create a 2D flattened drawing.  In a blank file, insert your survey figures.  Then go to export Civil 3d file.  Choose the option to convert survey figures to 2D.  This will create a generic Autocad file with polylines of your survey figures. Check the units of the file, for some reason if you were in survey feet it creates a file in feet.  Change the units if needed.  You now have a file that you can copy the lines to a Civil 3d blank drawing for hatching or whatever.  Or reference this file into a hatching file and if the figures change, then do another export, and reload.  Many ways to use the file but better than explode, convert 3d to 2d, and flatten, plus your curves remain.

[rl_jackson]

To create a surface from your data you would simply open a new drawing and do a survey figure and point query  into the drawing, this creates a light wait surface that can be dref'd into other drawings (Note this drawing only has the surface in it and nothing else). Prior to doing this you'll need to make any edits that you would normally make in the planimetrics file. I generally do this and even go so far as to create additional figures for various stepped offsets  and other items that I might need that were not originally coded in the linework. I never create a 2D plan file, I always draw in 3D, as my thought is that if I was doing a design and I was tying into an existing curb line I would want that line to be at elevation so I could set the new curb line at that same elevation.

[jefflambert9091]

We have a lisp for cleaning up the survey figures. One command, five seconds. No need to destroy everything. 

I have come to the conclusion that we will always have two drawings. I do like having the surface in its own drawing and a datashortcut. Keeps the main drawing files smaller. 

(defun c:FLATTEN_SVFIGURE (/ OSVFGR e1 e2 ss)
(setq OSVFGR (ssget "_X" '((0 . "AECC_SVFIGURE"))))
(if (/= OSVFGR nil)
(progn
(setvar "qaflags" 1)
(command ".explode" OSVFGR "")
(setq e1 (entlast)) ;Set Marker for last entity
(command "convert3dpolys" "P" "") ;Convert 3d to 2d-makes new objects
(setq ss nil) ;clear ss
(setq ss (ssadd)) ;create empty selection set
(setq e2 nil) ;clear e2
(setq e2 (entnext e1)) ;Start gathering new items made
(while e2
(ssadd e2 ss)
(setq e2 (entnext e2))
)
(command "_change" ss "" "p" "e" "0" "") ;change new objects elevation to 0
(command "_pedit" "m" ss "" "l" "on" "")
(setvar "qaflags" 0)
)
)
)

[Anonymous]

I concur on the always 3D.  Just feels wrong to make a 2D file.  But in their defense it is easier for simple design projects where you just want to put a water line 4ft behind curb or something.  Also hatching a 3D file is sure way for a crash.

[_Hathaway]

We keep all our topo/existing conditions data such as points and figures and surfaces in one 3d file and consistently work on projects with thousands of points and some with over 10k points without any issues on the survey or engineering end.  

[jefflambert9091]

Our civil's xref the base map into their CD's and the do not want to see all the points or the surface from the BM. They do if its a detailed site. We leave it up to the Civil PM whether we leave them in or not. FYI the points that are blocks stay, just the non-plotted points go. They like to datashortcut the existing surface straight into the CD so they can control when its on and off or a different style for reference. Same with the other disciplines. We set the style of the surface in the BM to None. If they need to see the points they can xref the surface drawing. I tried really hard in the beginning to keep everything in one file, but I have come to like the two. Eliminates some bloat.

[LucasHicks]

We have the one 3D Topo file as well, surface not displayed and can be data referenced into any drawing for whatever style is needed, and no display plus symbology for the points.  I've started making a dummy file with just the points brought in and set to a scale of 1 to 1.  This can be referenced into any file design/grading file to "look" at the points for elevation, description, comments, etc.  With the scale set small it doesn't interfere with designing and then can be turned off when done.