Clustering datasets when zoomed-out

[c4b4d4]

I'm working with big datasets, and after have thousands of nodes FPS drops a lot.

Is there any way to achieve clustering? Like when I'm zoomed out, it's not that important to have thousand of nodes drawed at the same time. It'll optimize a lot the use of 3d-force-graph with huge datasets.

[vasturiano]

@kzka90 you can always group nodes and setup some interaction to collapse/expand groups.

Like in this example, click on nodes to expand/collapse: https://vasturiano.github.io/3d-force-graph/example/expandable-nodes/