I need to write up an article on the wiki about it (but am locked out at the moment), or maybe a chapter in a book.
😉
But, there are a couple of ways.
On PC, the Google Earth Connection lets you capture terrain. For a small area, this is fine, as it is built-in and convenient. But, for a large area - the three of us are in the mountains and need larger areas - I'm not happy with it because each bit of terrain is a new object and you have to make sure that you never move them out of their original positions.
On Mac and PC, SketchUp has a function to capture whatever terrain is shown in Google Earth. You can only zoom out so far and then capture is now allowed. Takes a couple of times to figure out the right zoom level. Each capture ADDS more terrain to your SketchUp model. You have to learn to overlap just enough to get continuous terrain, but not so much that you're adding unnecessary repetition.
The terrain grabbed by SketchUp (free download) gets a grayscale image map for some odd reason. So, before I move my position in Google Earth, I File > Save Image a color image of what was just captured. (I edit the image in photoshop later to brighten it up/etc and replace the image in my 3ds texture folder with the color one to end up with colored terrain.)
Once the SketchUp model looks decent, we're back to the Mac vs PC problem. On Mac, you have to have SketchUp Pro (the paid version) to be able to export the terrain as 3DS and then import it into ArchiCAD using the 3DS import 'goodie', resulting in a single object. On PC, if the Google Earth Connection add-on is installed, you can open the skp file from free SketchUp to convert the terrain to an AC object. A bit more futzing to get the color images to replace the grayscale ones for the textures then.
Finally, to locate the terrain relative to the building site, it is just an issue of repositioning the terrain roughly in 2D and then fine-tune in 3D. It requires that part of the terrain is your building site and that you have a modeled mesh/topo/boundaries or something that you can map to identifiable imagery from Google Earth.
Note: the terrain does not have to be contiguous! In SketchUp/Google Earth, you can grab your building site (for alignment) and then grab some mountain peak area to the north, one to the west, etc - all floating in space, basically, but providing the things that you want for determining your views. For sun studies, of course, you'll need to go continuous, so for Marc's illustration, the capture would look like a doughnut with the building site isolated in the middle somewhere.
Cheers,
Karl
One of the forum moderators
AC 28 USA and earlier • macOS Ventura 13.7, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB