Extremely large surfaces

[glauberad]

The project I'm working on is over a thousand acres. I got a existing conditions file from the surveyor with just contours and that file was over 70 megs. Just opening that drawing takes some time. So I'm afraid when I start the design work I'm going to have some problems. Recently I got the go ahead to upgrade my computer and I was wondering what would be the best computer set up to work with civil 3d 2014 in terms of processor, RAM, Graphics card, and whatever else you feel would maximize the use of the software?

[sboon]

Upgrading hardware is a good idea, but it's not the only solution for this issue.  First of all if all you only received contours then you have pretty much the worst possible source data for surface construction.  Go back to the surveyor and insist on better data - an xml file, TIN lines, or points and breaklines.  You and your computer will do less work, and you'll create a much better representation of what the surveyor intended the model to look like.

Before doing anything you need to consider how to organize the project drawing files efficiently, so that you're not bogging down the hardware/software.  You may choose to separate your EG surface into pieces, or just build the whole thing in one drawing but that drawing will include nothing but that surface and its source data.  Autodesk has a white paper on working with large data sets (Can't find the link at the moment) which should be helpful.

Steve
Please use the Accept as Solution or Kudo buttons when appropriate

PS:  Large is a relative thing.  The surface I'm currently working with is 933,600 acres and includes 643,000 points

[neilyj666]

I'd agree with this

PS that is a large surface although I had to convert to a real area measurement i.e. hectares to realise this...:)

[jmayo-EE]

"Go back to the surveyor and insist on better data"

OMG yes. Your surveyor needs to leave the 1980's immediately. 😉

[Kevin.Spear]

Unfortunately, there is nothing pushing surveyors past the 80's. Well, i suppose the contract, and subsequently the income, will change their processes.

So that really is the motivating factor!

[neilyj666]

I suppose it is something that the OP actually got any form of CAD data as pdf seems to be the medium of choice for many these days.

[jmayo-EE]

I can stand getting pdf's for CAD work. The PC is as slow as a snail. I will typically print them and scan them to png since we don't have a real version of adobe.

[Neilw_05]

John,

I don't know if you are aware of the Snapshot tool in the free Adobe reader. You can grab a page from a PDF and paste it into Paint and save as PNG, JPG, etc. It's not as time consuming as print then scan.

[neilyj666]

Yes it is - I use PDF-Xchange viewer as this can export pdf to all the popular image formats - may save you some time (and ink) by not having to print and then scan...:)

[Neilw_05]

Most surveyors have had to deal with terrain models since LDT days and should know by now to submit points and breaklines or LandXML.Perhaps more often the situation occurs because someone didn't ask for the raw data in the first place, either because they didn't have a need for it (architects) or because they don't understand it's value (non-techincal staff).

I would think that data exists somewhere in the chain that brought the file to you. I would suggest to the owner/client that getting that data could avoid some costly issues down the road.

[jmayo-EE]

Neils (plural),

THANKS! You both know how I love to save time. 🙂

[jmayo-EE]

Hey Kevin. Many surveyors are stuck in the past but not our good friends here. 🙂

[rl_jackson]

Have to agree with that comment, I had a site like that done in LDD, back in 2002 and converted a 60mb file to about 2mb. Go figure, referencing data is great

[ericcollins6932]

Aside fro mquality of data, your best bet is to create a surface in that file and then create a reference (DREF) so you can access it from amnother file. Much more efficient.

[Funkychesta]

okay my problem is that i'm getting my contours from LIDAR data, or aerial topography off a GIS layer from the county. The county has these data sets you have to download in regional blocks and so getting another data set would take a few gigabyts to download and process (a couple days work). I finally got the contours clipped to my parcel but the contours still leave a good 70mb file. Now the surface doesn't have to be super accurate because they are for vineyard plans and i only need the contours to look at drainage patterns and figure out slopes. What is the best way to load my drawing without having it crash all the time. I know my hardware is not the greatest, but I have no way of upgrading for now. I can run 20mb files relatively smoothly, and I just need a way to get my file or surface simplified in the most accurate manner possible, or find out the best way to use xrefs or data shortcuts to make my drawing file actually usable. any help please!

[Neilw_05]

If you are stuck with using the contours one important step is to weed them when adding them to a surface. Typically polyline contours have vertices 2 to 5 feet apart along their entire length. If you add them to a surface without weeding, you end up with a very dense TIN since the triangles will be formed using all those vertices.

Consider a contour that is fairly straight for some length. All those vertices along that length are not adding any accuracy to your surface. By weeding them you reduce the density (and file size) of the resulting TIN without reducing it's accuracy.

[Funkychesta]

thank you! so I should pick a number between 2 and 5? or just play around
with it and see what kind of accuracy it yields and balance what is
acceptable?