Topographic survey deliverable

I submit a surface model.

We use C3d in our office, and the engineers want a drawing with 2d elements only (which they xref) and a drawing with the C3d surface model only (which they insert). They also like a separate drawing with cogo points only.

Outside clients get an xml of the surface, unless something else is requested.

Nothing wrong with discussing project needs with the client beforehand and tailoring the deliverable to their needs.

I too submit a Triangulation Surface model.
They get it in whatever format they want. 3d AutoCAD and/or 12d ascii are the most common.

I build my surface model in C3D as well. And 9 times out of 10, the client says something like, "Well, we are just using plain AutoCAD. Can you just send me the drawing with the points turned on?"

Then, when I do, they call back and complain that the points are "overlapped" or "hard to read" or whatever. Then they expect me to go through and manipulate each and every point to display at the scale they want and not be overlapping with the text of other points nearby nor of the topography line work. /sigh/ I just send the points file in both a .txt format and a PDF of them printed. It almost seems absurd for me to even bother doing the work to build a surface that they will never use...

skwyd, post: 336577, member: 6874 wrote: I build my surface model in C3D as well. And 9 times out of 10, the client says something like, "Well, we are just using plain AutoCAD. Can you just send me the drawing with the points turned on?"

Then, when I do, they call back and complain that the points are "overlapped" or "hard to read" or whatever. Then they expect me to go through and manipulate each and every point to display at the scale they want and not be overlapping with the text of other points nearby nor of the topography line work. /sigh/ I just send the points file in both a .txt format and a PDF of them printed. It almost seems absurd for me to even bother doing the work to build a surface that they will never use...

"It almost seems absurd for me to even bother doing the work to build a surface that they will never use..."

How do you create contours without creating a surface?

Jim in AZ, post: 336588, member: 249 wrote: "It almost seems absurd for me to even bother doing the work to build a surface that they will never use..."

How do you create contours without creating a surface?

Well, that's the problem. The end user isn't utilizing my contours or my surface. They are just basically "scaling" from the topo points. It's quite frustrating.

A story.

I began surveying in 1988 and by 1997 I was pretty good at the small lot jobs, minor partitions, site topos, and ALTAs that my enmployers did, like so many do. I had a friend working for one of the larger engineering firms in Portland, and they were working on some pretty cool transit (ie/ light rail transit) jobs. With his help I got hired on.

Just before I joined they had prepared mapping, with surfaces, of miles of downtown Portland for the proposed streetcar line. But the surface was a botched job. The surveyed points were fine, but the person who had prepared the surface hadn't applied the breaklines properly and the surface model was not reliable. The rail enginering team - an outside consultant - designed to whole transit line by interpolating between the points and ignoring the surface. Needless to say that was arduous and time consuming. Because the surveyed surface was a botch.

At that time I was clever enough at surfacing a parking lot with C&G but I had no clue with Softdesk/AutoCAD. But I figured it out in time.

About a year later an extension to that same rail line - about a dozen blocks - was planned and I was assigned the job. This time we made up a surface that worked. I submitted it, and shortly thereafter called up the tech at the outside consultant who I knew was doing the legwork. I asked if he had checked out the surface, if it was working for him.

"Oh, we don't use the surface. It isn't accurate enough for us." he says.

"Well, try this one, Alex. It's good. Try it out." says I. He agreed to look into it, grudgingly. He was, and is, a nice guy.

Next day he calls me up just as exited as can be. "That's awesome. I've already done more work than I could have in weeks on the first phase" he gurgled. "Can you fix the old surfaces?"

"Well, not without higher dispensation. I just haven't got the budget for that.

" Can you at least fix about 2 blocks back from were you started this one? That would be save so much time."

" Yes, I can do that."

Old Alex was practically giggling as he hung up the phone.

The point is that engineers are used to getting crappy product from surveyors. Good surfaces and topo drawings are the exception, not the rule. So, of course, they don't bother with surfaces at all.

I always include the 3d faces in my drawing in a separate layer. If someone wants to create a model it is easy to do from these 3d triangles. The model is valuable when quantities are needed.

Norman Oklahoma, post: 337381, member: 9981 wrote:
"Well, try this one, Alex. It's good. Try it out." says I. He agreed to look into it, grudgingly. He was, and is, a nice guy.

How is a surface actually used in the field? Is it just an accurate representation in CAD of what the pre-construction surface looks like? Is it first integrated with whatever is being built (rail lines, foundations, roads, etc.), in CAD, then output points sent to the field? Is there any field (i.e. DC) software that can "carry" an entire surface into the field such that one with a robot and prism pole could stake new the desired surface in real time in the field (or using machine control)?

rfc, post: 337383, member: 8882 wrote: How is a surface actually used in the field? Is it just an accurate representation in CAD of what the pre-construction surface looks like?

A surface, or digital terrain model (DTM), is a model of the ground surface. And not just exisiting ground, although that is what surveyors are usually called on to produce. It can be a planned ground surface. Engineers use them to design a planned work. By combining their plan surface with a surveyors existing surface they can model storm water runoff & earthwork volumes, etc. etc.

rfc, post: 337383, member: 8882 wrote: Is there any field (i.e. DC) software that can "carry" an entire surface into the field such that one with a robot and prism pole could stake new the desired surface in real time in the field (or using machine control)?

Yes ,absolutely. Most modern data collectors (less than 10 years old) can stake to a DTM.

It isn't easy producing a surface in C3d from 3dfaces. For some reason C3d won't accept 3dfaces as data for a surface. You first have to employ one of the many lisp routines available on the internet that converts 3d faces to 3d lines. This may be more than your average Engineering tech can handle.

I always supply a separate file that includes the TIN and contour lines.

Another story...

In 2004 I was with a small company that was sharing space with an engineer. No corporate relationship, we were just sharing space and expenses. The engineer would give us a chance to propose on his jobs needing survey, but we had to compete for each job. Often his clients selected a surveyor without his input. So it goes.

Anyway, I got to see his engineering tech in action a lot. He would get "surveys" in from various sources, almost universally without contours, let alone DTM. Usually the shots that were in these drawings were not sufficient to produce a decent DTM either. But this tech needed an existing ground surface DTM, so he would make one from whatever data he did have, often cobbling up data points to fill in the gaps as needed.

When we were lucky enough to get the job for these guys we would always produce a carefully crafted DTM. We took a lot of pride in our DTMs. We would package it with the drawing file and deliver it, Land Desktop style, which the engineering company used ,too. AND - WE WERE SITTING AT DESKS IN THE SAME ROOM WITH THE TECH.

(Guess how this story goes from here.)

The tech would ignore our surface and create his own from our point data. Of course. That's how he rolled. We were basically the only surveyor he dealt with that delivered DTMs and he just couldn't help himself. We would watch him do this and say, "whaaat the f... are you doing , Brad?" He would stammer and claim he didn't know we had made a surface. We would ask where he thought the contours came from. "Well, it too late this time, I've already done it." The scenario repeated several times over, like Groundhog Day it was.

Anyway, the point is that these techs usually don't get a surface so when they do, they don't know what to do with it.

You are getting in the tech's rice bowl.

(The Sand Pebbles - 1966)

Mark Mayer, post: 337390, member: 424 wrote: It isn't easy producing a surface in C3d from 3dfaces. For some reason C3d won't accept 3dfaces as data for a surface. You first have to employ one of the many lisp routines available on the internet that converts 3d faces to 3d lines. This may be more than your average Engineering tech can handle.

Pardon? Civil3d has accepted 3d faces as surface data for quite a while - I believe that we were doing it in the 2008 version. I just ran a test here using 2016, seems to work fine for me.

I'll have to revisit that. Thanks for the heads up, Steve.