Progressive Rendering

This is a feature request and also a discussion on how to iterate on light building.

I’m fairly new to UE4 but I used Blender for a long time and my productivity with materials and rendering shot up when Blender introduced progressive rendering (where you can quickly have a glimpse of the final product and the image gets progressively better with time). I wish this feature was available in UE4 but I don’t know the technicalities behind game engines and whether this is possible or not. This topic was brought up in the ArchVis forum here:

As you can see from the thread, people struggle with iterating and trying out parameters when there is this huge time sink called light building. For level designers reading this, what techniques and hacks do you use to go around this?

I wouldn’t be surprised to see this type of feature in the future, it would only be a way to get a preview of what lighting will look like, you would still have to mess with lightmass for the building process. Though a real-time GI solution might get integrated before then.

If it’s any help there are a couple of dynamic GI solutions they could show a lower quality version of what you should expect and you can bake it at key points to make sure it isn’t completely wrong. Just an idea LPV, VXGI and AHR are a couple of usable options they aren’t complete yet but it might help.

Thanks for letting me know about these. It seems only LPV is available in the engine, the others have experimental community builds

This remember me Source FilmMaker where I think the final render is done is steps, but the light or nothing in UE4 is done to work like that, and the Blender render use ray tracing something you won’t find here, that can’t be done in at all realtime atm.

Basically what you say is a offline render system and the game engine work totally in realtime, you can bake the light but nothing more here, and the light baker don’t work with the GPU as Blender do.

Realtime GI system won’t give you a real quality as in Blender or other offline render systems.

As far as quality goes I believe it’s LPV, AHR then VXGI. Yes that’s true LPV is the only one in engine. Some history on LPV it is actually third party code from Lionhead studios for their game fable legends as they were shut down by Microsoft all development has ceased but on the UE4 trello LPV improvements are listed so who knows. As for VXGI it’s a GI solution made by Nividia, Galaxyman2015 has done a lot of work on his own branch over in general discussion if you are interested in that. As for AHR RyanTorant is the man who made that he has done a whole lot by himself as of recently he’s also been working on a fast bake version along with a hybrid bake so if you’re interested in any of that he has a thing over in work in progress. Hope that helps. Oh and you will need to download from GitHub and compile with VS2015 for both AHR and VXGI.