The static smooth curves are based only on the positions of the connected nodes. There are multiple ways to determine the way this curve is drawn. This example shows the effect of the different types on a large network.

Also shown in this example is the inheritColor option of the edges as well as the roundness factor.
The roundness factor is only functional with "continuous", "discrete" and "diagonalCross".

To improve performance, the physics have been disabled with:
{barnesHut: {gravitationalConstant: 0, centralGravity: 0, springConstant: 0}}
and we have enabled the toggle hideEdgesOnDrag.