Visual Surface Quality Assurance

Tags surface, QA, QC, Surface Style, Volume Dashboard, TIN, grading, grading group

One of the best things about AutoCAD Civil 3D are the visuals that Civil 3D Styles and the backend AutoCAD display engine can produce. If we employ these capabilities to our advantage they are:

More Than Eye Candy

 A Crossover Corridor

These tools and capabilities can help us significantly check and vadilate our work with less time and energy invested in the effort. AutoCAD Civil 3D gets better and better at this sort of things with each release, service pack, or even some Subscription Advantage packs. 
A rich and tested set of what we call "QA" Styles (like those available in the Jump Platform products) helps a lot to get the work done faster and with more consistency.

Here's fairlly typical corridor for a suburban "crossover' - a connection between two parallel streets. The Baseline alignment contains two spiral-curve-spirals that are superelevated to AASHTO Green Book standards. This is something we support in the Jump Platform right out of the box.
A small hill in the existing topology is going to generate some cut and fill and the typical volumes problem. 

You'll notice that there's already a View Frame Group referenced in and Offset alignments have been set up to control the definitions of Sections when we get to publishing that.
The corridor currently has a Code Set Style in place that generates screened output in Plan.
There are already a number of surfaces that were develped for the corridor.
Time for some more QA before we publish things.

A Section Editor tour is always in order. Here we are at full super in the first curve.

The Corridor in the Section Editor 

A quick check of the Datum Surface with even a simple "Quick View" like surface Style (it employs just TIN Triangles and Points) shows we have some corridor frequency adjustments to make particularly around the critical superelevation points. Our corridor employs pretty rough frequency values at this point. An adjustment to the alignment geometry and then forgetting to rerun the superelevation wizard might easily produce  a bumpy road issue like this.

The Datum Surface with simple Surface Style 

We All Want a Volume

Time to break out that new Volume Dashboard tool Autodesk released late in 2011.
 Did you remember to go get it?
Where did that thing get installed? Oh yeah.
Toolspace>>Toolbox>>Subscription Extention Manager>>Volume Dashboard Extention.
Whew.
Autodesk please put these things somewhere in the Ribbon.

A Grid volume surface doesn't make much sense here.
We want a TIN volume surface.
We want to sample at the surface data points from both surface. 
The differential volume surface will show the difference between the EG surface and our corridor Datum surface.

Create a Volume Differential Surface

The Volume Dashboard

Volume Dashboard Results

Once again even our "simple" TIN View surface Style provides us some nice visuals about where a how the differential volume samples are generated. Each triangle here in Plan depicts the locations of the sampled prisms and the differential surface. Do things make sense? Do the additional locations from the EG surface really make sense? Are we really using the "right" and updated versions of these surfaces?

A Simple Volume Surface Display

Obviously the location of the differential TIN volume surface is not at the same elevation as our previous 3D view. Basic Invisible Styles were applied to the other surfaces clean things up.
A basic Shaded with edges Visual Style even without any tweaks clarifies the volume areas above 0' elevation nicely. Our Code Set Style (from our InstantOn Basic product) for the corridor visualizes just a plane in the 3D view. The subtle details of good Styles pay off big time. 

Since AutoCAD Civil 3D 2012 now includes "Elevation range banding from a Datum" we can create a new QA Surface Style to clarify the Cut and Fill.
Watch your back.
You are about to create something new in Civil 3D.
This is always dangerous. 
You ARE actually adding a NEW part to the engine while it's running.
Save and make things simple first.

Style Edit without Crash

Civil 3D 2012 will crash every time you attempt to initially apply this perfectly fine and valid surface Style unless you make things simplier on the display engine first.
The way the Civil 3D Elevation Analysis from a Datum of 0.000 initializes causes the ACAD display engine to croak when it is asked to generate this the first time in 3D viewports. Ouch.
Zero values are always dangerous. 
It's "No big deal" if you obey the basic Rules of Style Creation.
Use a single viewport in Plan view to construct, apply and TEST the Style for the TIN volume surface the first time.

Our Style documentation should look like this so others can follow what we've done...

A Banded Elevation Surface Style

We only want the Border and Elevations displayed in Plan and Model.

A Volume Surface Style Displat tab

The Elevation Analysis definition should basically look like this. Notice we're using 3D Faces and not another one of the 2D Plan type components to generate the ranges. These and really handy for Plan but we want a little more in this case. How you tweak the Range interval and precision also affect the results. Tweaking the Elevations Display Mode may make visualizing the results in 3D more demonstrative for you and others too. 

A Volume Surface Style Analysis Tab

Build and Test

The Surface Style building's done. We should update the corridor. Then we need apply our new Surface Style to the TIN volume surface and run the Elevational analysis to update the volume surface. The Civil 3D model is "dynamic" but we're still responsible to know the processes.

Apply the Surface Elevational Analysis

You can cheat and employ the Object Viewer and/or work on your View Cube and other interface skills to get back to two viewports with different views and Visual Styles applied in no time.

From a Zero Datum in Plan and 3D

Long before we get to this VISUAL point we need to seriously think about what we're going to do with the TIN volume surface and the new QA Surface Style we've created here.

Do you Manage the Dynamic Model in your projects?