Hello guys, I hope you’re doing well.
TL;DR, Blotches and strange shadows on walls and corners in archviz projects.
I work with architectural visualisation and I’ve been using Unreal Engine for two years now, Mainly for VR. So everything should be clean.
Unfortunately, It’s extremely hard to produce clean scenes and clean walls in particular.
I always have issues on each corner on almost each wall, specially the areas that are lit with an indirect light. Blotches almost everywhere, and strange light behaviours sometimes.
After spending tons of time of tweaking and faking my scenes, I manage to get better results, reducing the blotches and shadow errors and enhance the lightning behaviours.
but they are far from perfect. I’m not comparing to vray or corona but we should at least get some nice clean walls and shadows much more easily.
And It gets worse when dealing with large projects like an hotels or office buildings.
Where we have large Exterior and a lot of interiors.
I think It’s a good idea to divide the project in many pieces (Levels) to save performance and run the lighting tests on faster rate. but it really breaks the immersion.
Render times can get too extreme when we want really clean results, It’s very frustrating when we have dramatic increases of the time needed to bake the scene to get the same buggy results.
Here are some images from a projects I’ve been working on last recently:
All lightmaps are set on resolution of 1024. (all these images are on (4.15.3) (there will be many images I’m sorry about that)
Recently, I’ve downloaded modded version of Lightmass from Luoshuang and increased the lightmass settings within the engine
Thread: Lightmass: multi-bounced sky lighting - Rendering - Unreal Engine Forums
I’ve got better results but there are still some blotches:
I’ve increased the settings on lightmass by a lot but it did not changed anything,
I’ve edited lightmass INI file and I started getting better results but it introduced new kind of blotches:
After that, I’ve added spotlights with very low intensity on these blotches, most of them are gone, but the ones who left are so annoying.
These are some images from another project that I did last year and didn’t finish yet (just like all personal projects 
), It’s much larger on interior scale with high walls, I did not change INI settings nor used Luoshuang’s modded file of lightmass, it does look better but with there are still bugs, ( I did it on 4.13) and I think it was on preview with settings of
Static Lightning Level Scale 0.7
Num Indirect lightning bounces 20
Indirect lightning quality of 3.0
As you can see my main problem is the weird shadows on the walls and the blotches,
I’m not sure what’s wrong anymore … I used 3DsMax for 3d modeling, I do the 2nd UVs for walls by using SteamRoller script because sometimes I have hundreds of them and I do all other UVs manually. With decent padding between the UV shells.
What would I do to eliminate these blotches?
Thank you for reading and for your time.
