Georeferenced DWF Files

I have come to rely on my power users.  Just the other day one of my power users (Michael Elander) came to me asking about georeferenced DWF’s.  To be frankly honest my knowledge of georeferenced DWF’s really extended no further than a flier I picked up at AU or something on Design Review 2008.  The concept I understood, but how to create one, I just hadn’t invested the time to figure it out.

The whole reason Mike wanted to pursue the topic was because he was asked to share some drawings with a third-party who was not our client.  They needed to be able to reference our drawing, but we didn’t want them to be able to manipulate our drawing.  As many have discovered over the years, locking down a DWG file is easier said than done.  Sure there are some third-party apps out there, but what about the tools we already had installed?

That’s where the idea of the georeferenced DWF came up.  Since AutoCAD 2008 we can Xref a DWF, snap to the linework contained within it, and provided we enable them, turn layers on/off.  Translation: it’s essentially a DWG which the third-party can’t modify – perfect!

Converting a Drawings Coordinate System

For one reason or another drawings sometimes need to be moved from one coordinate system (datum) to another.  A classic example may be moving from a NAD 27 datum to a NAD 83.  Whatever the case may be, how might one perform this translation as accurately as possible?

To answer that I turn to good old Map 3D.  As you may know both AutoCAD Land Desktop and AutoCAD Civil 3D are built on top of AutoCAD Map 3D, so if you have either product, you also have Map 3D.  Users of Map 3D naturally know it's power, whereas I have found many civil engineering professionals nearly forget about the Map menu altogether.  While it may seem odd, we're actually going to start the translation from a blank drawing.

Finding the 3D in Map 3D: Surface Visualization

Flash The September / October issue of AUGIWorld is now available for download.  The cover story for this issue is "A First Good Impression".  Impression is a brand new program that Autodesk released this year which allows you to give your CAD drawings a hand sketched look.  Anyone faced with creating such exhibits and illustrations will definitely want to read this months AUGIWorld.

In addition to the "A First Good Impression" article, there are numerous other articles worth giving a read.  Of those articles is one by yours truly titled "Finding the 3D in Map 3D: Surface Visualization". AUGIWorld is available electronically by clicking HERE.

Download the September / October AUGIWorld

Importing & Elevating GIS Contours - Part 2

In my last post titled "Importing & Elevating GIS Contours - Part 1" I discussed a way for us to import GIS Data into an AutoCAD Drawing as AutoCAD entities.  While I spoke in context of using it to import GIS contours, truth be known, the process outlined in part 1 can be used for almost all GIS data.  Unless you are working with contours, you can probably stop with my last post. Contours (or topography) require a little more work to make them useful.

At this point we have a drawing full of contours, none of which have an elevation. Non elevated contours may be fine for some elementary tasks; more advanced tasks will undoubtedly require your topography to be elevated. If you?re a gluten for punishment, you could always click each contour line, changing its elevation. Thankfully such pains don?t need to be experienced as Map 3D provides us with a semi-automated way of elevating contour data by queuing in on a data field. So just how does one elevate their contour data?

Importing & Elevating GIS Contours - Part 1

Contours Perhaps one of the most common GIS related tasks I am asked to help with is how to import and then elevate GIS contour data.  Oftentimes this data is provided as an ESRI Shapefile, and when imported has no elevation.  While GIS contour data isn't accurate enough for precise design, it is often sufficient for the purposes of preliminary analysis or broad design considerations.

While the details of course vary depending on the data source, all GIS contour data generally share some fundamental similarities. Of these is the concept elevation data is encapsulated within a one of the data fields of your shapefile.  Elevating GIS contour data can be summarized in two parts; importing the data, and elevating the data.  Unfortunately these two parts cannot be done concurrently, and instead must be done separately.  In this, the first of a two-part posting, we will look at how to import GIS data as AutoCAD line work into a drawing.

Some things to note about this process.  First, you are actually importing the data into your drawing, not linking to it.  What that means is if your GIS data source ever changes, the data we import will not update.  While my focus will be on importing contour data, this process will work for any ESRI Shape file.  Something like contour data doesn't traditionally change all that often, whereas parcel data is generally changed daily.  Thus like anything, there are advantages and disadvantages to this process that you will need to evaluate.

Map 3D Drawing Status Bar in Civil 3D

Civil 3D users – did you know that Map 3D has a specialized drawing status bar?

It seems the typical Civil 3D user knows little to nothing about the abilities of Map 3D. As those who do use it know, Map 3D is an incredibly powerful geospatial tool. Autodesk did publish their "GIS Skills for Engineers" document with the release of AutoCAD Civil 3D 2008 and AutoCAD Map 3D 2008. For anyone who has to use GIS data in an engineering environment, the document is a must read.

In reading through the document one thing I noticed was its use of a drawing status bar I had never seen before. That got me to thinking, and in true CAD Geek fashion, on a quest for the answer for this little riddle. Finally after fiddling around for some time I was finally able to uncover the answer to unlocking this super top secret drawing status bar. I say super top secret because (to my knowledge) the Map 3D Status Bar cannot be enabled from within AutoCAD. So how does one enable it?

Thematic Mapping for Engineers

Thematic Mapping for Engineers 072707 1940 thematicmap11Since I know everyone out there has joined AUGI (Autodesk User Group International) this is likely old news. Just in case you haven't checked it out already, the latest issue of AUGIWorld (July/August) has a number of great articles in it including one from yours truly. Inside this issue is my article titles "Thematic Mapping for Engineers".

For years now anyone needing to analyze GIS data, identify trends, and ultimately create a map has defaulted to the industry leading ESRI ArcMap. Simply put ArcMap is a phenomenally powerful application. So powerful in fact, many users (especially engineers) barely utilize even a small portion of the software. Autodesk overhauled a good portion of the GIS data analysis tools in Autodesk Map 3D 2007. Using those new and improved tools, AutoCAD Map 3D now has the ability to do many of the tasks engineers have previously relied on a package such as ESRI ArcMap for.

Download the entire July/August AUGIWorld

Download "Thematic Mapping for Engineers"

Isolating Individual Objects

Isolating Individual Objects 061807 1749 isolatingin1Hidden for some time now in the lower right-hand corner of AutoCAD is a little light bulb. If you are like most, you have simply let this little light bulb burn –wasting electricity. At first glance it may seem a little out of place. After all light bulbs belong in the layer manager– right?

Even still – what's up with the light bulb in the lower corner of the screen? What many seem to discount as being a status notification of some sort is in fact an actual command.

Geospatial Data in a DWF file

In observance of the "National Orange Effect Day" The CAD Geek Blog is proudly displaying the colors of Virginia Tech - Orange and Maroon.

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Those of us who work with geospatial data (aka GIS Data) know how incredibly valuable the data can be. Living in the digital age of the 21st century, the one thing always more valuable than processing data is the ability to share it. Perhaps the most common file format for geospatial data is the ESRI SHP file. Although phenomenally powerful, the format is quite frankly rather clunky. It takes 5 separate support files to make a single SHP file to work. With Design Review becoming a free download the collaborative powers of the DWF format can now be realized. Of the powers packed into the DWF format is the ability to embed geospatial data into a DWF file. It is possible to embed geospatial data into a DWF, and it be available in Design Review.

Linear Quantities Made Quick

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As Published in the March/April 2007 AUGI World Magazine

Somewhere in the lifecycle of nearly every project there will come a time where quantities must be calculated. Regardless if they are a part of a review agencies requirements, or in-house needs insuring your project isn't over budget – calculating quantities is quite simply no fun. Granted base AutoCAD offers some impressive tools to automate calculating the number of blocks inserted in a drawing, but still what about linear features such as lines arcs and polylines? Calculating the total linear feet for each diameter of waterline in a project could easily take hours using commands such as PEDIT and LIST. At the end of it all you kick back in your chair and say to yourself – there has to be a better way? There is in fact a better way, and it is found within Autodesk's Map 3D software package. Using Map 3D it is possible to calculate linear quantities in a matter of minutes as opposed to hours. Making such a time savings possible are Map 3D's topologies. By design topologies are technically a GIS tool, but with a little imagination they can be quickly made an engineer's best friend.

Understanding Topologies

By definition topologies are a set of geometric connections between objects. While the definition may be a little cryptic, if one takes a moment to think about it, nearly everything illustrated in a set of engineering plans falls into this category. Take for example a waterline design. The numerous pipes (objects) will be assembled together (geometric connections) to ultimately construct a complete water system. Using a "Network Topology", statistics (including length) for such a waterline system can be calculated in a matter of minutes. Autodesk's Map 3D allows for three distinct topology types; node, network, and polygon. The different topology types mirror the different ESRI shapefile types of point, polyline, and polygon. Which topology to use will be determined by what type of entities you are working with. In our case we're interested in calculating the total length of waterline in our design. For linear features such as waterlines, a network topology is best suited for our scenario.

Structuring your Drawing

Although individual entities can be selected and added to a topology, breaking items such as your 6 in. and 8 in. waterlines onto two separate layers will streamline the creation of your topology. While it may seem elementary, taking a quick moment to insure no extraneous linework is contained on your layer(s) to be calculated will of course insure an accurate quantity. Taking a couple extra minutes to structure your drawing as outlined above from the beginning will make up to the minute quantities possible during your next design charette.

Creating a Network Topology

Similar to AutoCAD in the way it makes commands available in numerous ways, topologies can be created in one of two ways; using the Map Explorer in the Map Task Pane, or by working through the Map menu itself. Although both methods have their advantages, to keep things as simple and concise as possible this article will work through the Task Pane.

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  1. Open the Map Task Pane – The Map Task Pane loads by default with Map 3D (although you may have disabled it). Use the "MAPWSPACE" command to turn the Map Task Pane back "On" if you have closed it.
  2. Set your Task – The "Map Explorer" task pane will be needed to create a topology. Do note the slight interface change between the Map 3D 2006 and Map 3D 2007 releases. Map 3D 2006 uses tabs on the side of the interface – similar to tool palettes. Instead of tabs on the side of the interface, Map 3D 2007 (Figure 1) has a pull-down at the top of the interface explicitly labeled "Tasks".
  3. Create your Topology – Of the options in the
    Map Explorer task pane is "Topologies". To create topology right-click on the "Topologies" option and select "Create" (Figure 1).

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  4. Specify your topology type – As discussed earlier, there are three distinct topology types available within Map 3D; Node, Network, and Polygon. From the "Select Topology Type" dialogue box select the "Network" radio button. The title of the dialogue box should update to read "Create Network Topology – Select Topology Type" (Figure 2).
  5. Give your Topology a Name – Although you will likely discard your topology after calculating its length; you still must give it a name. Use something logical. If calculating the length of an 8 in. waterline a logical name may be "WATR-08IN" (Figure 2). You may choose to also provide a description although it does not affect the functionality of the topology command. Press the [Next] button.

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  6. Select what to calculate – Upon pressing the [Next] button you will be presented with the "Select Links" dialogue (Figure 3). Quite simply, the "Select Links" dialogue is merely asking what entities you wish to add to your topology (and ultimately calculate the length of). Within the create topology command there are four distinct ways objects can be selected; all objects, by object, by layer, or by class.

    In this case we're interested in calculating the total length of 8 in. waterline. Thanks to a little upfront work, this particular drawing has a separate layer for each pipe diameter. For that reason I can simply select the layer name that contains my 8 in water pipes (C-WATR-UNDR-08IN). Had this drawing not been structured with each pipe diameter separated onto its own layer, the manual selection method could have been used. Objects may be added to the topology manually by clicking the button to the right of the "Select Manually" radio button. If you hover over the button the tooltip will read "Select Links".

  7. Finish your topology – Even though the create topology has a couple more dialogue boxes, enough information has been provided for Map to generate a linear quantity desired. Thus at this point we can press the [Finish] button.

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  8. Gathering your Quantity – With your topology now defined, statistics can be calculated on it. Back at the "Map Explorer Task Pane" right-click on the name of your topology and select "Statistics" (Figure 4).

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  9. And the number is… - After selecting "Statistics" a new dialogue will appear. The "Topology Statistics" dialogue will display a number of statistics about your topology. Admittedly most will be interested in but one number – the total (Figure 5).

Command Line Version

An interesting fact about Map 3D is the way most Map commands have the ability to function in a textual command line based interface. Consistent with most standard AutoCAD commands, prefixing the command with a hyphen "-" will suppress its graphical dialogues, and inherit a command line only functionality. Most humans will of course prefer the graphical dialogues. On the other hand, by using the command line, regularly calculated linear quantities have the potential to be automated with a script. The two Map 3D commands used in this article were: MAPTOPOCREATE and MAPTOPOSTATS. Adding a hyphen to the –MAPTOPOCREATE command will allow a topology to be created from the command line. It's important to note the command prompts for the MAPTOPOCREATE command are not in the same order as the dialogue boxes are. The command line version of the command asks for nodes to be selected first. Nodes were not used in our scenario, and thus can be skipped over in the command line version of the command. Be sure to add linear entities as links when using the command line. Unfortunately there is no command line equivalency of the MAPTOPOSTATS command. Although the command cannot be controlled from the command line, it doesn't make knowing the command a worthless bit of trivia. Typing MAPTOPOSTATS (without a hyphen) at the command line will result in its graphical dialogue being launched. Tagging this command at the end of an automation script would still guide a user in the right place, allowing them to quickly calculate a linear quantity. It's no secret; the engineering design process is very iterative. Despite that known fact clients rely on design teams to provide accurate and up-to-date take off's to insure their project is on budget. Municipalities are also traditionally eager to know these same quantities for purposes of budgeting future maintenance costs. Regardless of who the quantities are being calculated for, up to the minute quantities can now become a reality. Although the topology tools are more focused towards GIS, they can prove invaluable on the engineering side by saving both time and money.

Autodesk AutoCAD 2008 Release Dates

After taking a look through some reader feedback it seems a fair number of you have reached my blog looking for the release dates for the 2008 civil product line. In light of that response I went out and did some searching of my own to uncover what, as best I can tell, are the official release dates. I have only included the products which most civil firms will likely be interested in. So without any further a due…

DWG True View 2008
(FREE) – Released March 15, 2007

Design Review 2008
(FREE) – Tuesday, April 17, 2007

AutoCAD 2008 – Friday, March 23, 2007

AutoCAD Civil 3D 2008 – Monday, April 16, 2007 (aka Tax Day)

AutoCAD Map 3D 2008 – Thursday, April 5, 2007

AutoCAD Land Desktop 2008 – Monday, April 16, 2007 (aka Tax Day)

AutoCAD Raster Design 2008 – Friday, April 20, 2007

Autodesk VIZ 2008 – Thursday, March 29, 2007

Again, I have done my best to verify those dates, but again as with any software release is subject to change for any number of reasons. Feel free to post a comment if you find any of the dates to be incorrect.