Something like this seems to work:
using AbstractPlotting
scene = Scene(camera=cam3d!)
linesegments!(scene, [Point3f0(0) => Point3f0(1,0,0),]) # I've found the scene has to contain something first
# To print to console whenever the view changes:
foo = lift(x -> @info(x, scene.camera.projectionview[]), scene.camera.eyeposition)