Terrain from Shape file contours

[Benson Shaw]

I imported shapefile contours from QGIS into vwx. Very happy with the nearly automatic georef process for this.  Geometry came in as 2d polys with attached records in the OIP data tab.

 

For the site model source contours, how does one convert the 2d polys to 3d with the z value assigned from the Elevation data field of the 2d poly?

 

Thanks!

 

-B

[Tony Kostreski]

Hi @Benson Shaw

 

Use the command Modify by Record found under Tools>Records>Modify by Record. Select the appropriate Record and Record Field and under Modify select Elevate 2D Polys.

 

Modify by Record with shapefiles are a lot of fun! Another great example is extruding all buildings to their known height automatically 😉 or, EVEN BETTER, using this Marionette script, 2D to Massing Models, that converts them to Massing Models while maintaining their floor usage. 

 

 

Best wishes,

Tony

[Benson Shaw]

Hi, @Tony Kostreski !  Many thanks!  That works a treat!  It took some prodding and mushing around, though.  Here are a couple of the foibles which might trip up others:

 

I downloaded Contour,  Pavement Edge and Building shapefiles from City  data hub. Parcels with prop boundaries are from County data hub.

1.  I noticed belatedly that the imported contours were not to scale, nor were the building outlines.  I finally solved it by changing the order of import.  Buildings first.  Then contours.  I think the problem is an out of date or corrupt Projection sub file in the Contours (it's from 1993, the others are all from 2016 or later).  Anyway, importing building.shp first created proper projection, scale and locations in the vwx file. Subsequent imports of the shp for contour, pave edge, parcels, etc matched.  Took a bit to discover.

 

2.  Source contours imported with several segments at each elevation, rather than continuous lines. Each segment has its own ID record. I made a duplicate set and composed. No problems with 3d conversions or Terrain generation, but I did notice that the ID record adopted the highest ID of the former segments.  Would this kind of record merging cause problems? eg in IFC or other?

 

3.  The modify by record action for contours did not work at first.  The contours moved up by only a few inches off the layer plane instead of 2' increments starting about 280'.  I looked into the contour record format and found that the elevation field definition was Integer.  I changed it to Number/Dimension and the contours converted quickly to 3d polys at correct z. Yay!

 

4. Same record problem with the building outlines.  Changed the record definition. Then, the buildings extruded from z=0, showing a couple hundred feet of extrude below the terrain skirt.   I cut off the lower sections with split tool.  The extrudes maintain same record values.

 

OK, thanks again @Tony Kostreski  and forum for the help.

 

-B

Edited May 13, 2020 by Benson Shaw
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