Curve (Spline) options in OpenRoads Survey

Product(s):InRoads, MX, GEOPAK
Area: Survey



Is it possible to control how curves containing multiple points are drawn in OpenRoads Survey?

Is there a difference in how curves were drawn in SS2 Data Acquisition and in SS3 OpenRoads Survey?


There is a configuration variable that controls how curves are generated:


The two most common values for this variable are:

CIVIL_SURVEY_SPLINE_TYPE = 1     (InRoadsCubic - This is used by default if the variable is not defined.  This method generates b-spline curves using the same method InRoads survey used.)

CIVIL_SURVEY_SPLINE_TYPE = 2     (Curve - This is the method used by default in SS2 Data Acquisition.  If a user is seeing curves drawn differently in data brought forward from SS2, they will set the variable to this value.)

The following image shows what a curve might look like that is brought forward from SS2 Data Acquisition:



Default with no variable (CIVIL_SURVEY_SPLINE_TYPE        = 1)

The following is a list of  other values that can also be used.  These are primarily the same options used by the MicroStation "Create Curves" command:

0 = BiArc        

3 = Points         

4 = Poles        

5 = CatmullRom    

6 = ConicCurves    

7 = LeastSquares   

8 = LeastSquaresTol