Creation of contour lines.

This tool allows create the contour lines of a DTM.

At the command prompt, FlashMNT displays :

>> Select the 3D Faces :

Select the 3D Faces of the DTM, the the following dialog box appears :

Contour lines

• Contour lines model : Choose a predefined model or use buttons to Create, Save, Delete or Rename a model. Models allow you to create various configurations fitted to different scales.
• Order X : Orders represent the equidistances between contours. Order 1 would be the "master" contours, and orders 2 to 5 the intermediate contours. For example, Order 1 would contain contours whose equidistance (the Interval) is 10 m, Order 2 would contain contours whose equidistance (the Interval) is 5 m, and Order 3 would contain contours whose equidistance is 1 m. Intervals must progress in decreasing value. For each order you select, you have to set the following values :
• Interval : Equidistance between contours belonging to this order.
• Layer : Enter the name of the layer in which the contour will be created, or click on to choose from a list.
• Width : Enter the polyline width.
  

Filter elevations

Check this box to limit the elevations between which the contours are drawn.

• Minimal elevation : Enter minimal elevation
• Maximal elevation : Enter maximal elevation

Entity type

Describes the type of entities used to draw the contours

• Simple polylines : Creates non smoothed 2D polylines.
• Smoothed polylines : Creates 2D polylines smoothed by one of the methods described below.
• Splines : Creates Splines. This option is not available in BricsCAD.

Smoothing type

• Simple : Uses the FIT option of the PEDIT AutoCAD command.
• Spline : Uses the SPLINE option of the PEDIT AutoCAD command.
• Internal : Uses an internal algorithm.
• Density : Enter smoothing density (option "Spline" or "Internal" only)
• Simplify :"Internal" smoothing only : Check this box to reduce the number of vertices of the smoothed polylines. In this case, indicate a tolerance value.

Erase contour lines layer

Check this option for the contents of the layer to be erased a the launch of the command.

Remarks : For better speed and precision, use the "internal" smoothing method.