Any way to change or replace objects only on render?

hphoenix

Is there any to 'intercept' nodes on the way to the renderer and alter their geometry/properties?

 

I suppose I could simply 'hide' nodes that need altered and add a 'replacement' node, then post-render remove the added 'temporary' nodes and unhide the originals....but that seems like a very roundabout way of doing it.....