Parcels Have Priorities - Part 4

Tags grading, Label Style, Parcel Area Label, parcel, site parcel

Why does the Site Parcel’s Feature Line collector have a single Style-based Priority property? The need for the property isn’t really apparent at first glance. It becomes more evident when we begin to understand the depth of the Site Parcel and the dual power of the built-in Site Parcel model.

In the last post, we discovered a couple of really good dynamic reasons why Feature Line Style-based Priority property does matter. For Feature Lines we need a way to say this surface input data is more important than that surface input data.

The Parcel Posts - a study guide to Read and Test in AutoCAD Civil 3D
Site Parcel Essentials – Part 1 | It’s Not Yo’ Daddy’s Parcel – Part 2 | To Edit Parcels is to Create? – Part 3 | Parcels Have Priorities - Part 4 | A Strange Universe of Parcel Inverses and Mapchecks – Part 5 | Dances with Parcels – Part 6 | Pack Dances with Parcels – Part 7 | Cycle Manipulations of Segments – Part 8 | Select Manipulations of Segments – Part 9 | Visual Manipulations and Many Segments – Part 10

There is some interesting or funky stuff regarding Priority going on with Parcel display.

Site Parcel Display

The Site Parcel topology model does not have separate formal Civil 3D Styles and Label Styles of its own.
I personally believe strongly that it should. The whole model is something different and potentially useful than what we have today in Civil 3D. What about area volumes related to a visible whole model for example? In any case…

The collection of Parcels is itself is a separate resolved Parcel Feature. This Parcel is definitely not the whole model. This beast is the outer boundary of all resolved Parcels.
Remember that the “Parcels” do not have to be “attached” to one another either. It is possible to have Parcel(s) A and Parcel(s) B that share no segments in common. That collection of Parcels (the outer boundary) will also contain other disconnected and unresolved Parcel Segments outside the boundary.

A Site Parcel with Unresolved Segment

Disconnected and/or unresolved Parcel Segments on the “inside” are members of the internal resolved Parcels. Maybe that isn’t intuitive, but it’s true.

We Get Resolved Labels

By default, in all new Sites the Parcels collection is assigned an Area Label Style of <none>. There isn’t one. If we chose to assign an Area Label Style, for the sake convenience the collected Site Parcel’s Area label is automatically placed at the lowest X and highest Y location of all the Parcel Segments.

For resolved internal Parcels the Parcel Label location is apparently computed by a radius distance and bisected angle algorithm to always fall within the boundary. It is not the parcel centroid location.

When we make Gradings inside the Site Parcel, the Grading Label location employs yet another behavioral algorithm based on both segment and Grading Criteria midpoints.
Where’s Waldo? We all love the find the Grading Label game.

Refresh Your Accountability

As always the appearance of Parcel Segments and the Area Labels is a matter of Style. Whether we want the collected Site Parcel’s Area label and Parcel Segments to display or not is up to us.

When we make changes to the arrangements of the segments in a Site, the Civil 3D Toolspace and the screen display do not always automatically reflect the current “resolved” state of the model. Often we need to remember to manually Refresh the Parcels collector.
It would probably help us all if the dirty Parcels icon in the Toolspace was a bit more colorful.

If you employ the AutoCAD Undo command to return to a Site Parcel model to a previous state, the Parcels collector in the Toolspace can get seriously out of wack. A SAVE and a REGENALL seem to force an update.

Edit with Style

Doing Parcel design and build you may find it handy not to employ classic Area labels with the usual text stuff. Because of the Grading and Land chop duality tasks of Civil 3D Parcels, we often have more than one Site. Often we start out or end up with exact geometric duplicate Parcels.
You can employ a crafted set of symbolic Area labels (circle, triangle, square, etc.) to help you reach down “between the cracks” and select the “right” Parcel when you have multiple Sites in the mixer.

These Parcel Area Labels and some new nifty Parcel Styles are included in the latest InstantOn Basic for AutoCAD Civil 3D 2013. The Jump Kit for 2013 has even more of these – as usual.

Parcel Segment Display

An Invisible Site Parcel

Here the same Site Parcel collector with an “Invisible” or “No Display” Parcel Style applied. The “boundary” Parcel Segments disappear completely. All the unresolved segments (not inside any internal Parcel) disappear as well.
The other visible Parcel Segments assume the Parcel Style of the internal resolved Parcels.
Remember some of these segments are the identical Parcel Segments.

Funky Ain’t They? When we talk about segments on the edges, Parcel Style can be confusing.

Parcel Segments can be and often are shared by multiple resolved Parcels. The Site Parcel collector has a Display Order Priority property to allow us to sort out how we want the Parcel Styles assigned to the Parcels to be displayed. As we sooner or later discover Display Order Priority simplifies somewhat the Parcel Segment display, but it does not solve every annotative publication issue.

Escapes from Danger for the Unwary

If you assign an Invisible Parcel Style to a Parcels collector, you may create Parcel Segments and even Parcels than remain unseen but none-the-less comfortably exist in a Site Parcel. This is like drawing a line on a Layer that is OFF.

It is also possible to create a multi-segment Parcel Segment where no segment or Parcel EVER displays – Nodes can be just as easily stacked atop one another in a Parcel Segment as in a polyline primitive.
Beware! - It is also obviously possible to manually create and/or edit the nodes in a Parcel Segment into a strange stacked-node scenario that displays nothing or strange parts.

The Virtue of MAPCLEAN

It most definitely usually pays to process existing geometry work going into Parcels with Map 3D’s MAPCLEAN command. The MAPCLEAN process is worth more than a few posts and/or videos of its own. Suffice it to say with a bit of practice you can employ the MAPCLEAN tool iteratively to clean geometry much faster than manual cleanup.

Speaking of “topologies”, the AutoCAD Map 3D the underpins Civil 3D knows absolutely NOTHING about the unique Civil 3D Site Parcel “topology” even though Map itself has other topology features of its own. Don’t confuse them. Can you employ a Map topology to build the geometry for a Site Parcel? - You betcha. The results still require some MAPCLEAN.

The Package to Take Away Is?

Whether we get a Parcel delivered onto the Toolspace doorstep (resolved or not) is the first test of parcel integrity and the quality of underlying geometry data we put into the model. But because of the Parcel topology engine we don’t have to have perfectly matched 3D geometry to resolve 2D Parcels.

There’s more going on inside the Site Parcel.

Next time we’ll see how the Parcel’s internal Analytic property and other annotative tools play their vital QAQC roles.