Cross Sections

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A cross section is a geometry object containing either a pre-defined 2D shape, or a custom 2D shape composed of other polygons and polylines. Cross sections are used to generate 3D surface meshes by extruding the 2D shape along a path defined by another polygon or polyline. This makes it possible to create a wide variety of engineered surfaces for modeling.


By themselves, a cross section does not define geometry that can be viewed in the CAD window. Instead, a preview of the cross section shape is provided for clarity.




Polygons and polylines used in cross sections will use the detected coordinate pairs, since a cross section is a 2D object. This is auto-detected by SVDESIGNER, so as an example, the cross section will use X and Y coordinates if all the Z values are set to zero. Please note that the polygon or polyline used later for the extrusion path must use the full coordinate range, since the final object will be a true 3D object.


Data from polygons or polylines that may be unsuitable for use in a cross section will generate a warning. Be sure to consider the warning, as not heeding the warning may produce unexpected results. For example, the warning "Cross-section line AA is incomplete" typically indicates a polyline with vertical segments, which will produce multiple surface fragments when extruded using the road builder tool. This could be safely ignored if that result was intended or not required.