Most of the data in Powder Tracks is created via CZML content (CZML Documentation). This data includes all of the trail lines (Polylines), the skier’s path (Path), and the markers for videos (Billboard). See CZML files for examples of the various czml files that are loaded into Powder Tracks, and Loading CZML programatically to see how I loaded the CZML files into the application. The smooth camera transitions were created by determining the the position of the skier at a particular point in time and creating a camera flight from the current camera position to the desired end position (Camera Flight). The synchronized video overlays are quite a bit more complicated. Cesium does not currently have video support built in. We are slowly working toward supporting html5 video materials in the Video Branch, but there is no firm date for video support in core Cesium. Powder Tracks was originally based on the Video branch but has a number of additions to allow me to define video textured quads through CZML. If you really need video support, you can examine the compare between Cesium Master and Powder Tracks here. Nearly all the commits up through March 11 are to support video textures and synchronize the video with the animation clock.