September 2010


So, it’s not completely dynamic but, it may give you more flexibility then what you can get out of Civil 3D. Currently, the primary problem with Civil 3D line labels is that they can only have one rotation. What if I want to adjust the location of the line label and rotate it just a little bit so that it makes my drawing a bit more legible? Well, using C3D labels, that is very difficult to do as you would have to create a new label style for each rotation.

I think some people for get that the program we all use and love (well, love most of the time) is NOT Civil 3D, it is AuotCAD Civil 3D. It is built on the AutoCAD platform so why not utilize the capabilities of AutoCAD to assist us in those areas that still need a bit of work in C3D. In the following image, you can see a line that is labeled. I can take this label and adjust it however I like. I can move it off the line, rotate, and scale however I want.

How was this label created? Well, it’s simply a piece of MTEXT with a field inserted into it. I’m surprised at how many people are unaware of this capability, especially C3D users. I think it is because we get into the, “I have to use the Civil 3D tools to accomplish this” and we don’t think that perhaps there are other ways. So, what is a field? Basically, a field takes some data from someplace and puts it into a piece of text. For example, if you are creating a report in word and you number the pages, those page numbers are a field that says, “At this point in the text, put in the current page number”.

To create this label, create a piece of text (can be any type of text, I’m going to use MTEXT). If you are using MTEXT you can select Field under the Insert Panel on the Text Editor ribbon tab. If you aren’t using MTEXT, you can right click in the text editor and choose Insert Field… (or you can press Ctrl+F).

The Field dialog box is displayed. There are a lot of options here and I would recommend you take a look at some of them but, for now we want to label that line. Since we want properties from a line, you must select object. The upper left pulldown, “Field Category” simply filters out the field names to make it easier for you to find the specific field you want. The Object filter shows a four different possible fields, the one we want is Object (go figure!). Moving to the right a bit, chose the object you want to get the properties from by pressing the button next to the Object Type text box and select the line in your drawing. The available properties for that object are listed, select the one you want, and then on the right you select how you want that information to be displayed. Click OK and you’re done. For this line label you’ll need to create two different fields:

These are the two fields I created. After the length field, I simply typed in the foot symbol ‘. Since this is simply a piece of text, you can scale it, rotate it, move it, make it annotative, etc. If the line changes, the fields will update according to how you have AutoCAD setup. If you leave it set default, do a regen and you’ll see the text update.

Here’s a quick video that I did showing how this works:

This is a personal comment to other bloggers, please don’t create a blog post that is only a video. I often times will glance through the text of a blog to see if it is something that I don’t know or want to know more about and then I spend the time to read the blog. If it is only a video, I have to spend the time to watch the video to find out if I want to spend the time on the topic. I don’t mind videos but, please, don’t just do video blog posts!

Here’s a hypothetical situation, you’re a C3D users working with a client and that client wants a copy of your drawing. Well, they don’t own Civil 3D, just AutoCAD LT and, honestly, they don’t even use AutoCAD for anything other then simply viewing drawings. They aren’t going to be changing the drawings or anything along those lines. What do you do? Well, if you’re like most people, you’ll export your Civil 3D drawing to an AutoCAD drawing and send that drawing to the client. Well, I have one word for you, STOP IT!

Before I continue, I’m not going to say that you should never export to AutoCAD, there are some very valid reasons to do so (such as needing to open a C3D 2011 drawing in C3D 2010) but, in the above situation, the recipient of the drawing just needs to see it and perhaps review and comment on it. There is a better alternative – .dwf

So, why use .dwf? First off, when you export to AutoCAD, you lose all intelligence associated with those C3D objects, they become AutoCAD lines, arcs, and circles. If you have a point in C3D, there is an amazing amount of information associated with that point, coordinates, descriptions, user defined properties, etc. Export to AutoCAD and you only get the coordinates (possibly the elevation) and whatever information happened to be in the label at the time of export. Export the same drawing to .dwf, select the point and what do you get? Well, all the information you had in C3D!

The following image shows points in a .dwf file. After selecting one of the manhole points, you can see all the extra data that is available for this point.

If I had exported this drawing to AutoCAD, I would have lost all this valuable information! Another great example of data lost when exporting to AutoCAD is parcels. Export a drawing with parcels to AutoCAD, you get lines. Export a drawing with parcels to .dwf and you get, well, parcels!

Guess what happens if you select an alignment?

A pipe?

A structure?

A profile?

You get the idea.

Now, you may be saying to yourself, “But my client needs to use this AutoCAD drawing to help him draw something else!” Well, you don’t want him/her accidentally editing your stuff so, how about you send him/her a .dwf file and they can just xref the .dwf file into their drawing and use it that way?

There are many more advantages to using .dwf files (particularly if you are currently using .pdf files) but that’s for a different post.

Please please please stop thinking of a Site in Civil 3D as a site! It’s not!

In my C3D fundamental classes, I ask my students, “As a group of civil engineering professionals, what do you think of when I say the word ‘site’?” Answers vary but the typical ones are something like, “The project location”, “Project Limits”, “Area where work is to be done”, etc. When I first started to use Civil 3D, that’s what I thought of a site as well. I have some bad news for you, a Site in Civil 3D has absolutely NOTHING to do with location. I don’t think they could have chosen a worse word for this particular concept. I would much rather have it called what it is, a Topology.

“Topology? What is a topology?” That’s exactly why I think it would be better to have that name then “Site”. When someone new to Civil 3D sees the word “Site” they assume they know what it is because, well, about once a week they do a “Site visit” and at the start of any project, they get a “Site survey” done. If they had used the word “Topology” instead, a new user would look at that and, since they don’t know what a topology is, would not make the dumb mistakes I made as I was learning.

So, what is a topology? Well, basically it’s a set of rules that govern how lines (in the case of Civil 3D) behave as other lines change. When alignments and parcels are in the same site, the alignment will subdivide the parcels. When parcels and feature lines are in the same site, the parcels will alter the feature line elevations.

Here it is, my rule of thumb when it comes to sites, “The only time you should put ANYTHING in the same site as anything else is when YOU intentionally want them to interact.” In other words, unless you want these two things to react to each other, they shouldn’t be in the same site.

So, whenever you see the word “Site” in Civil 3D, just scratch it out in your mind and replace it with “Topology”.

p.s. White out doesn’t work so well…