Needing guidance with shadow/lighting artifacts

[anonymous_user_c570397b]

@preston42382

“any idea on why these emissive materials have such bad artifacts occurring?”

Could be an incorrect material network thing. A misplaced node, a wire that needs connecting to a different pin, the wrong blend mode…

If it’s only emissive, it should apparently be set to unlit. However, I think that’s primarily for performance reasons, not because that’s only how it works. Default lit works too, I think, but it would need testing to confirm. I think you’re right about it being an issue with the emissive strip lights. One thing I remember from a tutorial I did, but was for a different light type used to create a strip light is the diffuse boost is capable of making a non-emissive light (meaning it’s not a material that’s using the emissive pin of the main material node) become as bright as an emissive. So creating a different strip light that utilizes that diffuse boost setting could correct the artifacts. I’m not suggesting to delete the current strip lights, simply make new ones that are not materials that exclusively rely on emissive in the setup. Then compare / contrast what’s workable.

Do you know about IES light profiles yet? If not, look 'em up in the docs.

interesting, i’ll try the default lit thing. Also, do you happen to have said tutorial on how to create a light strip using diffuse boost? I thought diffuse boost was more for GI? Also yes, I do know what IES profiles are, are you saying I should use one on a strip light or something? I do like how the strip lights cast light against a surface without it but if it will fix the problem then I’ll look into it

[anonymous_user_c570397b]

Okay well I created a new project and made a long room out of basic cubes and lit it with an emissive light, and it works perfectly. Not artifacting. The lightmap resolution on all the cubes that make up the room is in the green too, not even the red. I migrated over that arch vis scene to the same level and put it directly beside the cube room i constructed and used the same exact light with it’s same lightmass portal (used to light the cube room) to light the arch vis scene and still got artifacts in the room with all the walls set to the RED in lightmap resolution. For a bit I thought the issue was from a couple walls in the room that it was saying had over lapping UV’s of about 6-7%, so I deleted those and re-baked lighting and still got artifacts on the walls that it didnt say had any overlapping UV’s even with the ones that were overlapping deleted. thought for a bit that it might be the material itself on the walls that was causing the issue so I replaced the material on the wall that had major artifacts with the basic material that comes standard on the basic cube I used to construct that long room. Nope, still artifacting.

with this test, it looks like the emissive light strips arent the problem but something else perhaps. no clue really what it could be? you can see that it lights the wall that it’s close to and the ceiling okay minus the area near the window. and the floor seems to be lit well too. but that one wall is really bad

[anonymous_user_f26c856c1 (anonymous_user_f26c856c)]

…if there is no shadow detail to visualize of course you can get away with lower res lightmaps!
…if all settings are the same and material is the same then I’m guessing it has to be the mesh…

[anonymous_user_c570397b]

@preston42382

Can you share that project file through here, such as a link to it in a cloud service? I’m really curious as to why it continues having the artifacts after those changes, and even putting it in a different project. The emissives shouldn’t cause that horrible of artifacts, and I’ve seen it before elsewhere, yet don’t remember where. I’m going to start a sort of archiviz project today, but moreso to do testing and tinkering with lighting and placing assets. Another thing is lightmap resolution should not have to be 1024 or above to look clean and high quality, especially on smaller assets such as walls, doors, windows, floors, etc. It is capable of enhancing the appearance of those assets in lighting and reflections and such, but from how I understand it, higher resolution adds a huge amount to memory usage. That, as a result, produces larger build times, loading the scene times, visual hitches, and uses up texture memory that can be utilized for other materials and things.

yeah i am totally down to share it. What file sharing service would you recommend? thanks for being willing to look into it with me! The model that I was using for that lighting example I showed pictures of earlier with the artifacts on that one wall isnt even from sketchup. its from an archvis starter pack i got from this post ( New Archviz Interior Rendering sample project now available! - Unreal Engine ) which is really set up for good lighting, so it’s weird. Still get similar artifacts on my sketchup models though. cheers!

[anonymous_user_c570397b]

@preston42382

There’s Google Drive, MS OneDrive, and a free 30-day trial of ShareFile. Whichever is alright, I think. I have a google account, so it’d go without having to set up a new account, but that’s not difficult either. I just encountered an issue where the sun / skylight is stuck at the horizon. I can’t move it above the level geometry to cast shadows now lol. That’s weird it is happening from a starter pack. It might be a hint to the cause of the artifacts. The best lighting I’ve seen in my own projects was in a starter level that’s part of a beginner tutorial. I didn’t change lighting a ton in it though in using it, so I think it is really an issue of wrong settings for various artifacts rather than a bug. Bug is an overused term in computer lingo.

nice ill look into google drive and get back to ya! interesting with the skylight. in that test level I dont even have a sun/skylight its just a PPV and lightmass.

[anonymous_user_c570397b]

As a workaround, I’m wondering if its possible to stick a point/spot light inside of an emissive material (that isn’t emitting any light) without it blocking off the light or creating a shadow from being inside said static mesh? If possible how would I go about this? I seem to have been able to emulate strip lights pretty well with just elongating a point light, but I would like to be able to turn fixtures I’ve bought that have emissive materials for the light bulb filaments or whole light source itself into something that emits light without having to use the “use emissive for static lighting” feature to turn a static mesh into a emitting light. When you apply an emissive material to a static mesh does it automatically allow light form a point/spot light to pass through or do I have to do something in order to achieve this? Thanks! Would be great if I could still use an emissive material that looks like its emitting light but its using a normal point/spot light to emit that light instead of the static emissive setting which I cant seem to find the problem with.

[Bits360]

@P.O.P.O

i’m using 4.24, ill leave the directional light stationary then and try setting those other settings for it if nothing else works by process of elimination haha

awesome! sounds good. I’ll prob do that when I’m getting closer to the end build because im assuming that ramps up bake times by doing that? I’ll keep it in mind, and report back to this forum if I still can’t find the issue after trying everything that you guys have suggested

Dont forget to bake at production when possible

[anonymous_user_c570397b]

Yes I’ve been told many times to bake in production but it doesn’t fix emissive artifacts. That was prob the first thing I did to see if it would fix it. I’m going to send my project to someone to see if they can find the issue but I’ve given up on trying to find it myself. If you read through the posts you can see the tests I’ve done and how it’s prob not the emissive lights themselves but how they interact with certain meshes. It works okay on basic static meshes you can find in the editor like cubes cylinders etc but not others brought in from different sources. (It’s not the material either)

At this point in prob going to try and find a way to put normal point/spot lights into an emissive to have that emit light instead since they don’t artifact the surrounding meshes I’m trying to use (no idea why they don’t but emissives do). Any guidance on how I could go about placing a normal light within an emissive material (that isn’t emitting light) would be greatly appreciated because I have many light fixtures I’ve obtained that use emissives but I can’t use them because of this problem.

[presto423]

There’s also converting a point / spot light into a 3D actor such as a cube or other mesh without using emissive, then apply the emissive material…but not sure if that’d solve it. It would probably be useless since it simply changes the light into a 3D model / mesh and doesn’t retain the light’s settings. Have you checked into creating blendables? It can utilize post process material to generate particular settings, one of which is emissive such as in a post process volume, I think.

[anonymous_user_c570397b]

I watched a tutorial not long ago (Unreal Engine 4 Emissive Lighting Tutorial - YouTube at the 3:21 mark) and this guy was using an emissive material on a cone, which he didn’t have emitting light and he was making it a movable flashing light by putting a movable point light inside it in a blueprint but kept the emissive on it to make it look like it was emitting light.

That would prob be the way for me to go here because if I
just created an emissive mesh the same color as my point light it would retain the properties of the point light but have an emissive mesh attached to it. If I can take my light fixtures and attach point/spot lights to all the bulbs than it should work while still being able to retain the emissives glow of the mesh.

Have to look into how he made the blueprint to do that more, k haven’t done that before. Any advice from anyone on here who has would be appreciated, thanks .