More Sketchup Tutorials
To extract approximate contours for an area, zoom into the location in Google Earth. Ensure your view is head-on and north-oriented. Go to Sketchup, and click on the Get Current View in the Google Earth Toolbar. Once imported, turn on the Toggle Terrain option.
Draw a rectangle large enough to encompass the entire surface, and then position it vertically as high as possible for the top contour. Select the rectangle surface, and then copy it down along the Z-axis your desired contour distance. Repeat this copy enough times to cover the entire terrain vertically.
Select all the new rectangles, and perform an Intersect with Model. Delete the rectangles by selecting their edges. Your new contours can be exported to Autocad or manipulated directly in Sketchup. Please remember the contours in Google Earth are interpolated and inaccurate for most locations, so these contours should only be used as approximations.