1. A concise explanation of the problem you're experiencing.
PolyLines across the antimeridian are getting distorted in 2D view. Does not matter if the polyline is from lon = -200 to -160 or lon = 160 to -160
2. A minimal code example. If you've found a bug, this helps us reproduce and repair it.
4. The Cesium version you're using, your operating system and browser.
Cesium 1.36, Windows 10 64-bit, Chrome Version 60.0.3112.90 32-bit