I finally succeeded to make paged vegetation using Ogre's paged component. I choose to go this way, instead of using the PagedGeometry plugin because I wanted to minimize dependencies of my application, and also because I wanted an unified paging system (and was a little curious about how it works underneath too!). As I was already using Ogre's paged component for terrain, I choose to take some time to implement PagedGeometry features directly... Here are the results (note that the tree model is horrible, but it's ok for my tests):
Each tile contain 50 instanced entities (using Ogre's new instancing manager system), batched together. The performance is quite good, I have a nice 2100 fps on my 2 year old computer :). Each tree is, for the moment, randomly positioned/oriented/scaled on page loading.
Next stage will be to generate impostors for far tiles, see how to implement paged grass, saving pages, and integrate the instancing shaders in my deferred engine.
