12da to from GIS: Difference between revisions

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|"-zln"|| When converting a .mif file to .12da file, if zln is specified polylines are interpreted in the same manner as a TUFLOW 3D breakline (see Read GIS Z Line) such that any points snapped to the polyline are used to set the elevations of any vertices along the polyline that do not have points snapped to them. The first attribute in the .mif file must be the Elevation. (Note, when converting in reverse from a .12da file to a .mif file without any options, 12da_to_from_mif automatically creates a .mif/.mid file suitable for use by Read GIS Z Line.)<br>

This is useful for creating 3D polylines for 12D where an elevation does not exist at a vertice. It is particularly useful where a river’s bathymetry in a DTM is being created from cross-section surveys, and the DTM operator wishes to use the elevations at the cross-section survey points, but needs to put more shape into the breaklines being digitised between the cross-sections so as to carve out the river’s bathymetry into the DTM. Using 12da_to_from_mid with the zln option will interpolate elevations at every string vertice, something that 12D does not offer (as far as we know!).

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|"-hip"|| When converting a .12da file to a .mif file will include any 12D hipdata polylines.