Assemblies: Look Wrong but Build Right

If you don’t know what I’m talking about, I hope I can prepare you when it happens to you.

When laying out Assemblies sometimes the overall look can wrong, some subassemblies will even include a label “Layout Mode” to let you know that when processed in a corridor will look right.

Assemblies are building blocks to build a corridor, and are NOT intended to be plotted, we have Standard Details Sheets for that. . I’ve notice this behavior in the Generic Link to Marked Point and some Medians.

Looking at a MEDIAN assembly, this one is closing the gap from Left to Right hooking to the MarkedPoint (triangle), with positive grades crowning upward.

When built in the corridor and placed in the cross section, the positive grades.

Now using the same subassembly on the other side of the median, closing the gap from Right to Left. This time we will hooked to the MarkedPoint (triangle) will cause the subassembly to flip.

Because the median subassembly had to flip to connect, the original positive grades are now inverted too.

Why isn't my pipe round?

Have you ever tried to show a pipe crossing in profile view or section view and it looks like the following:

As you can see from the screen capture, it looks more like a hex nut  rather than a pipe.  The cause of this is a system variable called FACETDEV.  The default value for the variable is set to .5 feet.  This variable works very similar to how the mid ordinate distance does for contours.  Civil 3D is drawing small line segments to represent the circular pipe.  If you change the variable to say .01, you end up with what you see below.

This is probably what most of you would expect to see.  I would like to point out that this variable will hold if changed in your corporate template, meaning you should only need to change this once.  Lastly, you may notice some drawing performance depending on how low you set the value, so you may need to play with it to get the right balance between performance and display.   

Template Tricks

I was recently asked by a IT manager if I have any creative tricks for stream ling the template creation process. In this blog, I will go over two such techniques I use.   The first technique I will go over is getting the object layers assigned in the template.  Typically, I chose to make all of the objects layer with a C3D- prefix, unless the client has some predefined ones.  So an example of this would be C3D-Alignment.  Now, rather than type each one, we can open a drawing/template with all those objects layers all ready assigned, like the one shown below.

Now with the blank template as the current drawing, I only need to edit the drawing settings of the other template/drawing that has the object layers assigned.  I then select the object layers tab and simply hit OK.

As you can see from the screen capture below, the object layers have been transferred to the blank template.  

The second trick I like to use is to have three predefined pipe networks all ready created within the template, which you can see in the following screen capture.

It is important to note that these networks are networks in name only, and they don't currently contain pipes or structures.  Now what they do contain are object layers, like you can see in the capture below.

By having the networks predefined, the user doesn't have to set these layers when they start the pipe network creation process.  All the user needs to do is edit the appropriate network, and start laying out pipe.

Intersecting SURFACE Boundaries

Some time ago... a day, a week, a month, who knows, I wanted to compare 2 TIN Surfaces and figure out the EXACT location of where the Surfaces touched. Ended up coming up with these steps: 

         1. Create a TIN Volume Surface 

         2. Ran am Analysis to User Contour Elevation 0

         3. Then Extract the Created User Contour as a Line 

Start by Creating a New TIN Volume Surface

(in this example a POND will be compared against a CROSSING plane) 

The Volume Surface is calculated from elevation 0, it will appears below the TIN Surfaces. 

To simplify view set TIN surfaces to No Display, and leave VOLUME Surface on

The Volume Surface is shown here using a Tin & Points Style. Notice how the Pond hole is filled up. A Surface Analysis to a User Specified Contour needs to be done to find the intersecting boundary.

Before running the Analysis, make sure the User Contour component is visible in the used surface style. The color has been changed to RED for it to stand out in Plan View

Then the VOLUME Surface Properties dialog box to the Analyses Tab, Select User-defined Contours as the Type. Presses on the Range to 1 and In the Range Detail area set the Elevation value in the row to 0.00

The result should be a POLYLINE marking the location of where the 2 Surfaces intersect.

The resulting Boundary Outline can be extracted. By selecting the surface and going to the Contextual Ribbon. From the Tools Panel use the Extract Objects and Uncheck everything except User Contours.

The final product is a 2D AutoCAD Polyline, that can be selected and edited.

Depth Profiles from EG

  

Lets talk about 3 options to get create a Depth Profile in Civil 3D: 

First Option:

Creating a copy of the EG surface profile it will be and exact match. We will then drop the copy the needed amount. However if the Alignment path were to change or Surface was to be edited the copy would NOT be up-to-date

     1. Use the AutoCAD command to copy the EG Profile. 

     2. Go into Profile Properties dialog box: Rename it, set a different Style and change the Update Mode to “Static”.

     3. Lower it using the Edit Geometry tools > Raise/Lower PVI Elevations command.

Second Option:

Creating a Feature Line from the Alignment and EG Profile that can be Projected and Lowered.

     1. From the Ribbons Home Tab > Feature Line > Create from Alignment.

     2. Choose of what profile to follow, Uncheck the Dynamic Link box and option set options to weed out vertices.

     3. Next add Feature Line to grid, Select the Profile View > from Ribbon > Project Objects to Profile View button.

     4. Make sure the “Use Object” is set for elevations in the Dialog Box Options.

     5. Lower the Feature Line the Ribbon or Right Click command to Raise/Lower.

Third Option:

Create a surface with EG pasted into it, NOT just a copy for we want the copied surface to be dynamically tied to the original. The down side here is duplicating a TIN surface will increasing the drawing size.

     1. Use the AutoCAD copy command to make a copy of the TIN Surface.

     2. From the Properties Rename it and set appropriate Style.

     3. Then use the Surface Edit command Raise/Lower to drop the elevation.

     4. Sample the new Surface to have it display in Profile View Grid.

Digitizing Points to Profile

I’ve been thinking about the many different ways to profile a “single file” or “in line” survey.  Surveys like this are common for a proposed utility run or cross section survey.  The need is simple, to profile these field points, but the issue is creating a TIN is just too cumbersome for the lack of supplementing point data.

We could add supplementing points manually or copy in parallel, but in this case we will do it without creating a TIN Surface:

1.      Draw 2D Polyline that connects the needed sequence of points

2.      Create Alignment from Polyline.

3.      Create empty Profile View from the Alignment

4.      Draw 3D Polyline connecting the needed sequence of points

5.      Project 3D Polyline to Profile View.

First, start by using the AutoCAD POLYLINE command to connect the needed points.

Second, using the CIVIL 3D command, from the Home Tab, to Create Alignment from Objects.

Once done with selection you will be prompted for alignment direction and choice to reverse.

Then on to the Alignment Creation dialog box, note that the option for Add curves between tangents is left unchecked.

Once command is complete, the Alignment and its Labels will appear.

Third, Select the created Alignment and from the Ribbon pick on the Profile View button to create an EMPTY grid.

From the Create Profile View dialog box, accept the defaults by selecting the Create Profile View button.

When prompted select a point on screen to create the empty Grid (this will be the grids lower left corner).

Forth, similar to before, using the AutoCAD 3D POLYLINE command to connect the needed points.  I found that if I freeze or turn off the display to the previously created Alignment, this will be easier.

Fifth, select any point on the Profile View grid, then from the ribbon select the Project Objects to Profile View button.

Once in the Project Objects to Profile View dialog box, make sure the option to Use Object elevation is set.

This will automatically populate the previously selected Profile View gird with the line.

This projected line work is dynamically tied to the original 3D POLYLINE, if it is edited, stretched, trimmed, etc.., it’s view in the grid will update.

Using Reference Text To Label Two Station Values for a Manhole

Within Civil 3D labeling functionality is a tool called reference text.  Reference text allows the user to label multiple objects at once, or allows us to label more than one type of object at the same time.  Examples of this would be labeling two surfaces at once, or adding an elevation to a station offset label.  The example that I'm going to illustrate here is labeling a manhole at the intersection of two roads that displays both station values.

                                                                            

            

 

As you can see from the screen capture above, once you select reference text from the label style composer, you will be given an option to choose what type of object you would like to make reference text for.  In my example, I will be choosing alignment.

In the capture above, you can see that I have added a reference text component called reference text.1.  I will rename this to something logical like second alignment station.  From this point on, we create the component like we normally would, and anchor the label.  In my label, you can see that I have anchored the label to the outgoing pipes, with it being displayed as ???.

Now that I have chosen the label that I created and selected the manhole, you notice that I have a pick box and some instructions on the command line asking me to select the second alignment.  I can now pick the appropriate alignment, or right click and I will be given the option to choose the alignment from the list.

Once I have chosen the appropriate alignment, you should see the question marks change to a station and offset value like the one seen below.

It is important to note that reference text component allows the user to change from one alignment to another.  If you look at the label in the AutoCAD properties box, you will note the reference text option at the top.

From within here, the user can select different alignments or components depending on the object created in the label.  If you hit the green box, you will be given the option to again select another alignment  .A great example where this can be utilized is when labeling a proposed surface. How often do we build multiple proposed surfaces to give the client various options of how the site can be graded.  A typical surface label is tied to the surface that we select when labeling, whereas a reference text label allows the user to use the same label, but change the surface it is getting the values from.

As you can see from the example label I created, the value of the reference text allows us to do multiple  labels within one label, or change randomly from object to object.