If you're using lots of lights with depth-mapped shadows, the renderer can spend
an amazing amount of time reloading the objects and calculating
shadow maps for each light.  The cure for this is either to cut down
the number of lights, or switch from depth-mapped to ray-tracing.

But in any case, Poser will sometimes get bogged down for no obvious
reason.  Don't be afraid to stop the render.  A restart, perhaps
after a reboot of the computer, may proceed normally.

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