What is a network layout?
In most data visualization practices, we map a column of data to a spatial dimension. However, in a network dataset, there is only information about how the nodes are connected. As a result, all the positioning information is relative and layout (literally, where to position each node) must be computed based on the information about the network structure. There are many known algorithms for computing network layout (also called spatialization) and the truth is that there is no “right” answer; network spatialization is an art and a science.
ForceAtlas3D Algorithm
The ForceAtlas3D algorithm was developed by Virtualitics and is a proprietary improvement on the ForceAtlas2 algorithm. ForceAtlas3D is a force-directed layout algorithm in which nodes apply a repulsive force on each other while edges serve as an attractive spring force between pairs of nodes. Furthermore, a gravitational force is applied to the overall system to maintain a reasonable scale. These 3 forces (repulsive, attractive, and gravitational) are computed and applied iteratively until the network reaches a stable configuration. ForceAtlas3D leverages GPU technology to get a substantial speedup in run-time.
When the algorithm has finished running, we generate 3 columns: Network X, Network Y, Network Z which are automatically mapped to the X, Y, and Z-axes so that the network can be rendered in 3D immediately.
Network Visualization and Structure