Traverses in the Alignmentstraverse group are LandXML alignments. TPC does not consider the closure when determining whether a traverse is an alignment or not.
Import Alignments (7:48) - Import LandXML alignments in TPC Desktop.
Importing
When you select LandXML Alignments for import, TPC creates a traverse for each alignment and sets the following parameters for the new traverse.
•Inserts the traverse into the Alignments traverse group
• Sets the traverse closure type to Closed Loop (but let's TPC change it if the parcels configuration doesn't close)
•Assigns supported LandXML attributes (state, length, description, etc). These correlate directly with LandXML data values and will be included in any LandXML export of alignment traverses.
•Inserts the LandXML geometry into the traverse
•Inserts the ProfAlign data into the traverses vertical curves
Import Details
If you turn on the [x] Details option when you import LandXML alignments, TPC will add information about the alignments imported like in the following sample:
[ Reading alignments... ]
1stave
Points: 2, Length: 773.58
Vertical Alignment: FGCenter
Vertical Curves: 4
Exporting
Traverses that are exported to LandXML, are exported as Alignments if they are in the Alignmentstraverse group.
Supported LandXML Alignment Geometry
TPC currently supports LandXML's Lines, Curves and Spirals. Chains and Irregular Lines are not supported.
ProfSurf Data
TPC does not currently import the ProfSurf data for alignments. This same information can easily be generated inside TPC as needed using the Transect command.
However, you can export ProfSurf data you create in TPC under a very specific set of circumstances as follows:
•The ProfSurf data to export must be in it's own, separate traverse in TPC
•The ProfSurf traverse must be part of the Alignment Profile Existing traverse group. You may have to manually create this group and place the traverse in it.
•The name of the ProfSurf traverse must immediately follow the alignment traverse and that alignment traverse must be part of the Alignments traverse group.
•The ProfSurf traverse must start with the name of the alignment traverse followed by a colon and space. For example 1stave: ProfSurf would the appropriate name for a traverse that defines the ProfSurf data for the 1stave alignment traverse.
ProfAlign Data
TPC support the ProfAlign data.
LandXML PVI vs ParaCurve - LandXML can specify vertical alignment with PVI's which do NOT include vertical curve lengths or ParaCurves's which do. If the data you import uses PVI's, you will want to consider letting TPC create the vertical curve lengths for you, based on grades computed from the PVI's imported from LandXML.
TPC allows unbalanced vertical curves in which the ingoing and outgoing lengths can differ. It appears that LandXML v1.2 supports only balanced vertical curves in which the incoming and outgoing lengths are assumed to be the same. This is not an issue when TPC imports LandXML's ProfSurf data since TPC can work with balanced vertical curves just fine. However, when exporting LandXML, TPC exports the combined incoming and outgoing lengths as a single length (per LandXML's specification) but adds the following text to the ParaCurve description unbalanced: in=length out=length.
