Newbie question about export/import for buildings

Hi guys,

(first, sorry for my english, it’s not my native language)
I’m working in 3d archviz on 3dsmax and vray/corona for 8-9 years and I would like to try unreal engine.
I’ve seen a lot of villa, houses, interior projects but rarely exterior buildings.
So, here is my questions :
I would like to try UE with one building archviz.
8 floors, 60 meter long for 20 meter wide. It’s not a big building but I have something like, 300-400 objects for only the exterior walls.
What’s the best way to work with all thoses box ?
Export all objects as single object (merge all), export each floor as single object (so, 8 objects exported) or export each object as single object ?

If I have to setup 300-400 lightmap resolution in UE one by one,… well, gonna be a long day. And if the objects are all merged, the lightmap resolution won’t be good.

Same question about the other object in the scene, windows frames, glass, railing, sils, … attach with each other, attach by floor, … ?

If I was working on a house, I will make it one by one, but here, with a larger building, I don’t know what the do.

Any advices ?

Picture of the building

If it’s just the exterior, it would work best if all of the outer walls are welded together–so instead of a bunch of boxes making up each level the side of the building would be one mesh.

This building should be easy to import in ue4. 400 objects is nothing. I’ve imported a 5000 objects building already!

1- leave all object as-is in your 3d modeling software. Generate your UV unwrap on 2nd channel for each objects (with the steamroller script for 3ds max) It’s a 1-click solution and you only have boxes to unwrap. Easy
2- Export the whole thing as a .fbx (Don’t need anything special like exporting each obj or group , merge, etc. Just export the scene like that)
3- Import in unreal, do not tick ‘‘combine meshes’’, do no tick ‘‘generate lightmaps’’ since you’ve done them in your 3d modeling software.
4- Once all your 400 pieces are in your unreal content browser, you select them all and drop them at once in your viewport, they’ll retain their position from your 3d modeling software
5- You can click CTRL+G to group them and move, scale them all at once. SHIFT+G to degroup iirc.
6- Select all 400 objects and assign a lightmap resolution override of 128 or 256 to start, bake… see how it looks.
7- increase lightmap resolution on meshes that needs it…

Try attaching into 4 objects:
First Floor
One of the middle floors(instance in UE4)

Since all the surface areas are close per floor you can get consistent lighting across the entire buildiing with the same lightmap size.

Thanks !
I gonna try all of those.
@heartlessphil : Ho ! I didn’t know how to override the lightmap resolution ! Thanks.

It’s best if you keep the number of objects low, since that will impact performance–while you might not care a whole lot about realtime performance it can get pretty crazy in archviz scenes if you don’t pay attention to that. Also, for lighting it helps if your flat surfaces are a single object rather than being made up of multiple parts.

hey i also trying to import interior scene by exporting fbx. but somehow its stuck importing at 75%
i tried to break the whole model and import it one by one but still it stuck at same.
any suggestion?


The lightmap override is where I always change my lightmap res. Faster than opening each mesh individually to change it.