I’ve found a few topics in which the request has been made for a function allowing users to bake individual or selected objects, but all date from 2015. Does anyone know if this feature will be implemented? Perhaps I’ve missed it in 4.12 & 11.
Especially at large environments it would be redundant to rebuild lighting for a whole city when all one wanted to bake was a lamppost.
Hi Mr Robville,
This feature request has been in for a while, as you may have noticed, but there aren’t any current plans that I’m aware of to work on this in the near future.
It’s a feature that was available in UE3 and wasn’t as hard to implement since the lighting was handled before anything else for Forward rendering, however, this makes it more difficult for Deferred rendering where lighting is applied after the fact.
This means that for something like this to build lighting only for a specific actors there has to be way to still calculate the bounce light of surrounding actors and how the lighting will affect this single actor to make it blend in well with the surrounding actors that already had their lighting built. This method will not be as fast as expected though.
You can follow the status and vote on it over here on the public issues site: Unreal Engine Issues and Bug Tracker (UE-10034)
Thank you!
Tim
Thanks a lot for your reply! It’s very understandable that there would still be a considerable amount of render time to bake the lightmap, though it will probably still save a lot of time in a situation I mentioned earlier where only a tiny portion needs to be baked and only involves any lights surrounding it. I guess that it would work best in enclosed environments as rooms.
Another advantage is if the lighting build keeps getting stuck on an object. One could then isolate the corrupted object more easily or in fact bake levels in parts when it’s not possible for the PC to run overnight.
Thanks again, I’ve left a vote!
Don’t underestimate the power of the Statistics Window to look at light build info as well. (Window > Statistics) Set the drop down in the top right to be Lighting Build Info and it’ll list all the actors in the scene that had their lighting built. Here you can see how long it took for specific actors. This can be helpful to track down where a light build may be hanging as well if it completes. A lot of times, it can be traced back to a specific actor here depending on its complexity and lightmap resolution.
This could probably be useful for you if you’re doing a lot of light builds. 
ATTENTION!! : Please CAST A VOTE for this feature here Unreal Engine Issues and Bug Tracker (UE-10034)
My vote is cast, thanks for the link.
