Should line through Earth be upside down V in 2D?

1. A concise explanation of the problem you’re experiencing.

We have a feature where we draw a straight line between locations on or above the Earth. This results in a strange-looking upside-down V shape for sites across the world when the map is made to be 2D. Is this a bug?

2. A minimal code example. If you’ve found a bug, this helps us reproduce and repair it.

Run example here and switch to 2D or Columbus mode.

3. Context. Why do you need to do this? We might know a better way to accomplish your goal.

Drawing straight (Euclidean) lines between arbitrary positions. Ideally we want the line to be straight-looking whether in 3D or 2D mode.

4. The Cesium version you’re using, your operating system and browser.

Most recent Cesium, using Chrome on Windows 10.

Hi Jacob,

This problem has been seen before. Enabling followSurface will help, but there will be some distortion. We’d require polylines to be connected using something called “Rhumb lines” which are not yet available in Cesium. The feature has been requested here. For a more thorough explanation on Rhumb lines, see this thread. For background, as a 3D engine, Cesium generally prioritizes 3D features over 2D features.