In Google Earth 6.1, two new KML features added to help you annotate line data and improve KML Tours that include Street View mode.
Earth 6.0 introduced line styling options to create more realistic roads that've a physical width, outer coloring, and text labels. Now, in 6.1 you can also add simple text labels at the midpoint of regular (screen <width>) lines by using the new <gx:labelVisibility> tag in <LineStyle>, explains Google Geo Developer team.
"To preserve the current, unlabeled appearance of regular lines in existing KML files, we've turned off all line labels by default in 6.1. Because labels for physical width lines were turned on by default in Earth 6.0, you'll now need to explicitly enable in your LineStyles to display them in Earth 6.1+," noted Google Geo.
Caption: Labeled line between SFO and LAX airports.
Better Street View experience in Tours
6.0 also introduced <gx:ViewerOptions> so that KML Tours can activate the historical imagery, sunlight and Street View modes, allowing you to tell even cooler stories.
Google Geo team explains "Street View mode uses a different field of view (FOV) than the regular navigation mode to provide users with a better experience. However, until now this special FOV wasn't captured while creating Tours in Google Earth. This meant that tour playback couldn't faithfully reproduce the Street View experience as originally recorded."
"To address this issue in 6.1 we added the <gx:horizFov> tag to <Camera> and <LookAt>. These values are captured automatically while recording tours in Earth 6.1 but you can also add them directly to your KML," informed Google Geo.
"Although Cameras and LookAts can also be used to provide a default view for your placemarks, please note that in Google Earth 6.1 custom FOV values are only respected within the <gx:FlyTo> tags in tours," added Google Geo team.