Realtime Lightmap

Read the title as "Realtime Lightmap Generator"

I know this has been announced for the Unity5 version but what I am looking for is a lightmap generator into the game during level loading (not the Editor).

Made an in game editor, mainly assets you import in realtime to build a stage.
They are some Unity's projector to simulate a few ambiance but it is to expensive for memory and draw call consuming.

I made a tool to combine assets by materials on stage loading to reduce draw call and objects in the scene.
But wondering if I could also bake the light information from the projectors on those object. (then I can disable them from the projector and to keep the player only affected but the projector).
I would maybe need something to generate a second Uv set...

Is there any technology into Unity or third party plugin that could achieve a such thing?
I do not know much this kind of technology. even I know a bit about polystripping, but not sure how to generate a very basic uv set... and also can the light information on each triangle... ( any reference would be appreciate!)


Thank you! :