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.

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The process to create the cross-sections from a 12D DTM is as follows:<br>

*Digitise the location of cross-section lines either in a GIS or in 12D. If in a GIS, export the layer out as a .mif file and then run 12da_to_from_gis to convert the .mif file into a .12da file. For example use:<br>

:This will produce a 1d_xs layer in shapefile format ready for use by TUFLOW and a .csv file for each cross-section line. Keep the 1d_xs layer and the .csv files in the same folder in the event that you move them elsewhere.<br>

Using the xsGenerator.exe utility, you can also assign material values to each of the cross-section points (see <u>[[xsGenerator | this page]]</u>).

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<tt>12da_to_from_gis.exe -out output_file.12da &lt;Lines&gt;.mif</tt><br>

Will create the file with the chosen output name instead of the default.

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<tt>12da_to_from_gis.exe -model 12d_Model_Name &lt;Lines&gt;.mif</tt><br>

Will embed the specified 12d model name into the created .12da file.

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= Examples =

<tt>12da_to_from_gis.exe -mif road_breaklines.12da</tt><br>

<tt>Read GIS Z Line THICK == mi\2d_hx_lines_draped.12da.mif </tt>

 

<span style="color:red">'''UNDER CONSTRUCTION'''</span>

 

=== CONVERT FROM GIS TO 12DA ===

 

Converts to 2D breakline.

 

&nbsp;&nbsp;&nbsp;interpolation of Z values at intermediate vertices.

 

 

=== CONVERT FROM 12DA TO MIF ===

 

&lt;Header&gt;.mif is any .mif file with the correct projection.<br />

Will search input directory for "Header.mif" or "Projection.mif" if omitted.

 

=== CONVERT FROM 12DA TO SHP ===

 

&lt;Header&gt;.prj is any .prj file with the correct projection.<br />

Will search input directory for "Header.prj" or "Projection.prj" if omitted.<br />

&nbsp;&nbsp;&nbsp;For conversions to .12da the "<tt>-model &lt;model_name&gt;</tt>" option can be used to set the model name.

 

 

=Frequently Asked Questions (FAQ)=