Hi, im trying to use UE4 for realtime archvis as we currently use a very outdated realtime model viewer but the asset library we use contains thousands of pieces of kit which would all require unwrapping. Most of the kit uses tiled textures or simple colour swatches. I dont understand why unreal needs uv unwrapped models if the texture is simply tiled across the entire mesh. Is there a way around having to unwrap every piece in our library because at the moment everything imports fine from fbx but the lightmaps just arent useable which is as expected.
Any guidance or help would be very much appreciated.
Thanks in advance
Jack
For textures there has to be some way of knowing how to map it to a mesh, which it can’t do without UV coordinates. If you’re already using textures and it looks fine, then it should work OK in UE4, lightmaps are another matter because they have strict requirements. UE4 has a tool for automatically generating lightmaps, though it doesn’t necessarily do a great job, which is a problem with all automatic methods.
Alternately, you can avoid using static lighting which wouldn’t require lightmaps, but you wouldn’t get as high of a quality of lighting.
If you aren’t too concerned about performance, Nvidia will soon be releasing a branch of the UE4 source that includes some of their Gameworks technologies, which includes a system called VXGI—a fully dynamic lighting solution with dynamic global illumination. However, it requires pretty powerful graphics cards to get good performance. If you used that you wouldn’t need lightmaps and you could have better quality dynamic lighting than the current dynamic lighting in the engine.
Do the automatic UV unwraps work at all for you? The system has been improved alot lately, I really like it now.
If you want to tile a texture across a mesh, you will need clean UVs. If it’s just a simple color, you can get away with automatic unwraps.
We use quadro cards so performance isnt an issue so that nvidiaVXGI sounds great!. I think i have worked out what i was doing wrong. i have created a second map channel with the auto flattened & packed uvs so the diffuse textures arent affected but it generates some fairly decent lightmaps for complicated objects. The auto uvs didnt seem to work for my object as it has a fair few different shapes, concave parts etc. Thanks for your help. I assumed it would take longer for a reply!
Jack
Automatic UVs is a great tool and has come a long way, but there are still limitations with that you may have noticed. It will not split any edges for UV shells. So when it packs it can still create overlapping UVs for some objects since it is simply repacking the diffuse UV’s shells.
Ie. think of a cylinder that has hasn’t had it’s side split in the UV editor. Since you can’t unwrap and lay that out flat it will generate a overlap issue, even with the automatic UVs in UE4.
I know you’ve already solved your issues but just good knowledge if you weren’t aware and good for anyone else who may come across this thread who has a similar issue. 
A note on Quadros—they are really bad at running game graphics, they’re specifically designed for working in stuff like Maya but in games they just aren’t very fast. You can get much better performance with a gaming card for much cheaper.
They seem to run our scenes fine however they are fairly simple. no characters with deformations etc just static scenes with a bit of foliage and some traffic. Not much in the scene really.
For anyone in the future who finds this thread, the workflow i followed was;
Split your model by matID (if your model uses multiple textures and isnt unwrapped)
select each split mesh and add the uvw unwrap modifier.
Increase the map channel from 1 to 2
select ‘open in UV Editor’
Normalise and pack.
Export FBX
Import into UE4 but uncheck ‘Generate Lightmap coordinates’
The lighting should now build correctly.
For more complex models of if youre a bit of a perfectionist you can manually normalise the uvs in max if you need more uv space for certain parts.
This method seems to keep all of the diffuse textures correctly mapped as they are in Max.
The final tip would be to increase your lightmap resolution if your shadows look a little strange.
It might not be the proper way but it works for getting quick visuals out of unreal.
Jack
Yeah, Quadro cards don’t speak ‘game engine’ very well. The Titan does, and all the consumer cards do. But the Quadro cards are optimized for high end stuff. They may work but you have to consider what the cards are for. A simplified answer would be that a Quadro card is designed to do stuff like render a film or design a building, a Geoforce card is designed to display complex stuff in real time. You can do your work with a Quadro but you’ll never know how it’s going to look on your client’s machine unless you’re certain they have a Quadro card as well.