Excluding objects from being build

Hello UE fans,

I have finished my lightmap uv’s for an object and I quickly want to check with Build if everything is OK. I’ve hidden all the other objects and I have unchecked “Visible” to rendering. But still everything is building and I’ll have to wait 20 minutes just to check this one object.

What did I miss? :confused:

Thank you very much!

Sorry for bumping this, is there realy no way to do this?

Unforunately, this option is missing. UE3 had a bake only selected option, but that feature hasn’t made a return. What you can do is make the lightmass importance volume only contain that one mesh, or you can use a small test scene for testing lightmaps.

Hi Hernavced,

We have a feature request in for this that is logged with UE-10034. At the moment this is backlogged though, so there is no ETA for when/if this will be added to the engine.

There is a work-around way of doing this that may help for the time being. I would consider this a “hacky” method, but it’ll work in this situation.

  • You can setup a sub-level by going to to Menu > Window > Levels.
  • Create new level and name it.
  • right click on the level and set the streaming method to “always loaded”
  • Select the objects that you want to exclude from the light build
  • Right click on the level in the Levels window
  • Select “Move Selected Actors to Level.”
  • Hit the EYE next to the level in the Levels window to hide anything from that level

At this point, when you build lighting since everything in that level is not loaded it will build without those assets.

There are some caveats to this though. If you place lights in hidden levels like this, there will be some bleed between the two depending on the brightness, radius, and other lighting settings. This is not a method to block lighting from being baked between levels, but it can work to exclude assets from your lighting build if you need to check a larger scene more quickly for whatever reason.

I hope this helps.


Thank you Tim, am following your advice and the one of ZacD. I hope this feature will be added, it’s very interesting for non hero objects.
I have a roof, pretty detailed geometry and I would like to texture this one with the AO baked in from my 3d app. So Unreal could ignore this object completely while building.

Hi Tim, I’ve followed your steps and it works with objects. But not with an instanced foliage actor. (my grass) which looks best without any light build. I have to move whatever the instanced foliage actor is attached to into the sub level which in the case of the grass is the whole landscape. Which when missing badly effects the light build. Is there a way to move just the grass to the hidden level?

Well, a very simple way is to switch the objects you don’t want to be built to “Movable” and the ones you want to include to “Static”, since “Build selected” is gone now.

Thanks BrickTop but for instanced foliage actors it won’t allow me to do that. For them there is no static or moveable option in the details panel.

If I moved everything I can into a sub level, could I build the lighting in there. Then turn on the persistent level containing only the grass?

YAAAAAAAYYYY!!!I’ve done it!! You select the instance foliage actors you want to hide using the lassoo tool in foliage mode. You then right click on the new level and it gives you the ‘Move selected foliage to level’ option. Which you take, and finally, after 3 hours you can go and make something to eat :slight_smile:

Very useful topic.
Tim, thank you for your advice and for detailed instructions on creating levels. It’s very useful for work.

I hid unnecessary levels but light building still as a whole scene.
What could be the reason?

Thank you.

ATTENTION!! : Please CAST A VOTE for this feature here Unreal Engine Issues and Bug Tracker (UE-10034)

tks!!! this topic save me

Hi guys, any idea why this feature request is backlogged? it could be so useful!

This bug still presented in 4.17, I don’t think Epic going to do any changes since it’s been requested 4 years ago first time and still present after dozen updates. Cross fingers for release 4.18

There aren’t any plans that I’m aware of to implement this sort of feature. It’d be nice, but as mentioned previously it wouldn’t provide the sort of improved build times users would expect.

Please consider adding this. It’s a major annoyance. Perhaps it makes less sense (in terms of urgency to consider it) for someone who started with Unreal, but coming from Unity, this is considered “standard”.

We are just starting our transition from Unity to Unreal, but so far, it seems like the whole hierarchy handling in Unreal is less object-oriented than in Unity. By that I mean that, in Unity, you can deactivate any node, be it a parent or a child within the hierarchy. Whatever is a child of a deactivated node will inherit this and also turn deactivated. You only need to uncheck a box on the parent node from which you want a branch or sub-branch to be deactivated. And by deactivated, I mean that the whole node branch is not only invisible, it’s not created at runtime. It’s truly void. It’s considered so important that it’s the first checkbox you encounter at the top of a node propriety (details section).

I’ve seen numerous request for this on various forums, spawning over many years. You need to catch up with Unity on this.


I’ve posted a previous reply here that didn’t showed. Sorry for the potential double posting…

Please consider adding this. The idea is not necessarily to save on build times…

It’s more a matter of when we prototype things, we may want to turn off certain “features” of our application. An other use-case scenario is to support multiple versions of a base-line code without the need to split into two completely separate projects. See, we are coming from the non-gaming commercial area. For our type of work, we often end-up supporting multiple customers using the same application / simulation product. But say we want to have multiple layers of complexity of the same product? Say you want to have various price levels for a given product?

In these cases, this simple switch would make lots of sense…

Thanks for hearing us.


make the object movable, and check that the “bake light as static” is off on that mesh