I have been using ue4 for a while and keep coming across problems when trying to light my scenes, can anyone help me with why my static lighting is blotchy like this, I have looked through a few forums and the ue4 lighting guide but cant seem to fix it, I have tired increasing the light map resolutions which doesn’t work and I have remade the models UV’s which doesn’t fix it. i am trying to capture the same lighting effects as the game called Inside
Post more information about your lighting and shadowing. Are you using Ray Tracing? Global Illumination? What are the settings of the lights affecting that particular room? What are lightmap resolutions for the walls and such in the room?
Those two screenshots aren’t enough to answer more exactly.
thanks for the reply 
it was an empty scene and I created a sky BP then directional light then sky light and then the height fog and everything has whatever the default settings are, ray tracing box is unchecked in the project settings the lights are static and the rest of the settings are default. the resolution is 64 I guess the default.
Try setting resolutions of all scene objects to at least 256. So, lights, walls, and shelf + other ‘loose’ objects. Is the skylight using a cubemap you made or was that part of it unchanged since placing it? Don’t use ray tracing yet, is what I suggest. It may also help to increase the number of bounces of indirect lighting by 1-3, in World Settings.
I haven’t changed the cubemap no, increasing the fog density has helped smooth out the light I also increased the resolution to 256 as you said and my light bounces are already at 3 ,there is still some lines and squares in the baked lighting though.
Try adjusting Shadow Bias of any / all of the lights, increasing past 0.5 but not lowering it below 0.5. Here’s a link to a doc page showing artefact lines on geometry from self-shadowing:
Or disable self-shadowing on the floors / walls. Those appear to be the only objects that the splotchy and line artefacts are occurring in those rooms. But it might require adjusting a few other settings to get the shadow darkness and lighting level intended.
Hi!
I’m guessing your lightmap compression is turned on, it will cause the first kind of blotchiness!!
The second one is a different problem and it’s not related to lightmap but your fog…
This worked a treat I thought it would be a simple silly solution, thank you!
I read an excerpt from the docs about shadow penumbras overlapping and causing artifacts, specifically that appearance of splotches. If it’s still there on the walls and elsewhere in the scene, I’d suggest adjusting the penumbra falloff of adjacent lights…and the penumbra of directional / sky light too. I think there’s also an Exponent setting under Lightmass settings or another set of lighting settings. If shadow penumbras (or basically the extent to which shadows reach based on lighting source angle and such) are overlapping, then it could produce those splotches and aliasing too.
I was just trying to do a baked lighting setup using stationary skylight and directional light in the 1st person template, with the shadow map resolution reduced to 512. Something produced wavy lines in the shadow edges of several cubes, but not all of the cubes. And all the cubes are set to the same resolution, movable, and have all the same settings that I set by selecting them all and changing them. So it certainly could be a problem of shadows from different sources interacting to produce such artifacts.