2. 3D layout generators

2.1. igraph_layout_random_3d — Random layout in 3D
2.2. igraph_layout_sphere — Places vertices (more or less) uniformly on a sphere.
2.3. igraph_layout_fruchterman_reingold_3d — 3D Fruchterman-Reingold algorithm.
2.4. igraph_layout_kamada_kawai_3d — 3D version of the force based Kamada-Kawai layout.