Harry Beck used a fish eye distortion for this exact purpose, when he designed the classic London Tube map in 1931. The scale is larger in the dense inner city, where the stations are closer together, and smaller in the outer suburbs, where the stations are further apart. The net effect is that the density of the stations is roughly constant across the map.
It's great that the distortion isn't done on a pixel level but rather at the object level -- it's mesmerizing to see the edges move ever so slightly when mousing over a region
Yes, it's an interesting 3D effect. From the article,
> This is particularly useful for disambiguating edge-crossings in static layouts: edges between distant nodes are distorted more strongly than local ones.
It's funny how the objects at the edge of the distortion are compressed; information here is lost rather than created. I'd rather see the distortion spread to the image boundaries. Then I can still see the whole image, but there is no weird annulus of compression.
Some compression is inevitable; to give space to some part of the visualization, you must to take it away from somewhere else. But yeah, there are variations of this approach that apply a global distortion rather than one localized to the mouse. For example, click on "Distortions" then "Fisheye XY" here:
[1] https://en.wikipedia.org/wiki/Harry_Beck