Generating Topology for Site Plan

[LakeTravis]

Thought I'd share a technique I've used for generating a site plan with topology lines.  Maybe someone has an even better way which I'd like to hear as well.  My goal was to generate a site plan for a 10 acre lot.  Something we could use to show where the house should be, where the drive should go, where some features should be.  In order to do this, I really needed to import topology into Home Designer (I use HD Architectural).  Here's what I did.

I had the boundary of the 10 acres plotted in Google Earth.  I then created a criss-crossing herringbone pattern throughout the entire site using the path tool making sure to have points in every corner and along every edge as well as up and down throughout the plot.  All told, I probably created about 150 path points.  Make sure not to join the ends otherwise it doesn't work for some reason.  Once the points have been added, I'd export the project from google earth as a .kml file.   I called this the 'elevation' view.  I then did the same thing except rather than create points throughout the interior, I simply created points along the perimeter.  Again, being sure not to join the path together or it doesn't work.  I exported that as a 'perimeter' view.

Now I used a tool like: kml2gpx.com to convert this kml file to a gpx file.  So end up with one gpx for perimeter, and one for elevation.

Here's where HD has some quirks.  HD allows you to import gps data but it only allows you to do it once.  So, first time around I imported the perimeter.  It's best to do this on a new project.  I wasn't ever able to move my house plan to the correct location in the site plan so I just didn't bother.  When importing gps data, HD asks whether it's perimeter or elevation.  Select perimeter.  The view will then have a nice outline of your lot.  The view will have north as vertical.  Now here's the quirk.  Since I can't import the elevation once I've imported the perimeter, what I do is copy the site perimeter to the clipboard and then select the undo button until we are back before the import.  Now I do another import of gps data, this time selecting the elevation gpx file and specifying elevation.  Once it is imported, I then go to "Terrain" -> "Build Terrain".  Voila, I now have all my contour lines on the plan.  I then paste the clipboard and my lot outline is added.  Now save it away so you don't have to do it all again.

 

I'm not sure why I couldn't import both gpx views but I tried for a while and just couldn't get it to work without generating the perimeter first and cutting/pasting it into the elevation view.

 

HD get's a little unstable after this.  I think because there ends up being a lot of elevation points.  But it's not too bad.  I've attached a pdf of the result.

 

Would love to hear if anyone has a better way of doing this.

 

LoganBranchN24c.pdf

[LakeTravis]

Thought I'd add a view of google earth with my zigzag pattern on it that creates the elevation points.  

 

zigzag.pdf

[Robborito]

Lake Travis,

This is interesting - and I am curious what these zig-zag lines or paths you added are contributing? The 'path tool' you used is in Google Earth - correct?

What is  happening technically here with what you have achieved - do you know exactly?

So you ended up with a terrain in HDPro that is based on Google Earth data etc...

Could you expand on the outcome you achieved for me please?

Thanks.