Creating a topographical map


#1

I want to create a topographical map of an 80 acre parcel of land in Michigan’s Upper Peninsula. Can anyone point me in the right direction to get started? (I found a YouTube video on the topic-- using SketchUp 8, Google Earth and something called Rhino 4, but this method doesn’t seem to work with the new SketchUp Make 2016.)


#2

Let’s be clear, please. I would take “topographical map” to be a 2D document with a flat representation of terrain by means of contour lines. Is that what you want to produce? Not a 3D model of the parcel?

What elevation data, if any, do you presently have?

-Gully


#3

Thank you. Yes, I want to create a 2D topographic map with contour lines.

I currently only have data–altitude, latitude and longitude-- from the four corner points of the parcel (marked as “Waypoints” on my handheld Garmin GPS). I could walk the entire parcel back and forth marking waypoints in a grid pattern, but I was hoping I might be able to just lift existing data from Google Earth.


#4

You’re going to get some, ‘why use a 3d program if you want a 2d topography’ comments but,
Open a new sketchup, go to Window then Model info
Click on Geo Location
Click on Add Location
Type in the address of your parcel, or the co-ordinates and search
then select region…and grab.
You’ll then have a Google maps image of the area you want and if you go to layers and turn on the terrain layer you will have an image that reflects the actual slope of the terrain.

If However you want the same thing with all the topographic lines in 2d, that is something else.


#5

You could probably get a ready-made contour map from the USGS.

However, all that to one side, contour lines are simply the intersections of a stack of evenly spaced horizontal cutting planes with the ground contour. So you could go ahead a grab your parcel of land using the Add Location feature as @Box outlined, then create a stack of horizontal faces (say, big rectangles, individually grouped) and superimpose them over the ground surface. Then using the Intersect Faces with Model command, you can create the contour line for each increment of elevation, one per grouped face. Finally. you would bring all the contour lines down to one elevation (presumably the elevation of the background image) and then make a 2D graphic image looking straight down on the array of contour lines.

And there you have it: your very own piece of 19th Century technology.

-Gully


#6

I don’t know where the height information in Google Maps is from, but whenever I have tried it (for sites in Finland), the result has been absurdly wrong.

Anssi


#7

I import contours from Autocad and create a Sandbox from there. I will then work on the model in Sketchup (v14). I then need to create a 2D representation in Autocad from what I’ve done in Sketchup i.e by exporting it. I thought of this solution but it is a touch long winded! I wonder, since this post, if any clever person out there has come up with an Extension which will create contours from a Sandbox model?


#8

http://sketchucation.com/pluginstore?pln=ContourMaker


#9

Thanks TIG, just what I was looking for…:+1: