Earth point measure polygon code#

To draw nice smooth arcs that end at ground level at each end we need to know what the absolute altitude of ground level is for each end of the arc – but this is not available in the KML file. KML does, however, support altitudes and KMLs derived from other sources, such as GPS’s, which include altitude, do correctly display the altitudes in Google Earth, and we actually used this feature when creating the arcs mentioned above. It is possible to set the whole path or polygon to either follow the terrain or be at a specific altitude, but you cannot adjust the altitude of individual points. KML paths and polygons that are drawn in KML do not have any altitudes associated with each point. Neither of these possibilities was satisfactory for the Santa Tracker as it often shows the arcs up close and Santa himself is shown following the arc and would bounce around alarmingly as he flies over mountains and rivers below. The other alternative is to use absolute altitudes but this results in arcs that end at a fixed altitude either underground or up in the sky, depending on the altitude one sets and the altitude of the ground at the ends of each arc. As we noted in that post, however, the arcs use relative altitudes, but for smaller arcs there can be noticeable dips and bumps in line with the underlying terrain.

Earth point measure polygon code#

When creating the Santa Tracker we made use of some code we had previously written for creating arcs in Google Earth.