Smudges on Objects: Lighting issues related with lighting and material

Hi everyone, I am a beginner kind of UE4 user and an **architect experimenting with UE and trying to adapt it to my workflow. There are many issues that I am having trouble with but this one is the most important one that makes me suffer. First of all, I want to talk about how I generate my models and my method to import them into UE4:

I use 3dsmax to make models, when the object is done, i convert it to mesh and add the UVW map for texturing and finally flatten the texture with **unwrap then chose the channel 2 **in order not to have lightmap issues in UE4. Forgot to mention, I reset all smoothing groups before texturing. Export it as **.fbx **and import it into UE4. In the editor, I select the UV map 1 and source lightmap 1 as can be seen in the attachement.

When these procedures are done, i chose the lighting quality production then build the scene. The thing is, when i build the lighting there are smudges appear on the objects. Nor is this all, **reflective materials looks awry **and the reflections of the light on the floor doesnt look all right.

I would be grateful if you guys can help me to solve these problems. Thanks a lot…

Maybe your lightmap resolution ain’t high enough? mind to show your UV layout channel 2 for lightmap?
reflection qualitty can set in postprocess in order to get more presentable looking but in engine the reflection is not so perfect compare to pre-rendered of cos.


UV unwrapping plays a very important role in Lighting. We can remove most of the smudges and artifacts with proper and clean UV unwrapping. Once, you have proper unwrapping you can play with Lightmass settings of
1 - Individual Mesh (Lighting -> Overridden Light Map res, increase this value till blotches and smudges disappear; Max 2048)
2 - World settings (Lightmass Settings)
(and Finally BaseLightmass.ini though IMO it’s not required to change ini values)

Please read the these following forum posts

rafareis123’s Lighting workflow

Lets make Lightmass EPIC (and understandable)

Yeah some of those are definitely a UV problem, You can try using a script like steamroller for 3dsmax (it’s free) that will automaticlly flattern your uv channels, It’s quite the time saver and it does a pretty decent job.

Thanks MSL, I read the links and they are really helpful. I increased the spacing value of flatten mapping in max also increased the lightmap resolution in UE4. Besides, I changed the lighting quality to production in order to avoid light leaks and did some experiment with the basemap.ini values. So the results are promising, not as good as v-ray renders at the moment, need more practise… I am sharing my settings down below…



And here is the result so far:

I will try out the script today Imsopov thanks…

So there are one issue left that needs a solution, as unwrap is crucial for good lighting and we need to unwrap every single object in the modelling software. How can we deal with complex objects that has a lot of polygons… I tried to unwrap a bed model in max which is nearly 200k poly, and it really took a long time, considering that i will have many furniture and whiteware in my house model, i would spend hours just for unwraping objects… Is there any shortcut for that?

You may find that steamroller may do the job for you. There are plenty of auto-unwrappers out there. I haven’t tried too many myself but I am thinking about getting unwrella possibly in the future for more intricate meshes like furniture etc.

You might want to break up your walls into smaller pieces. That way it’s not a single 512 lightmap for your entire scene.

you mean using a modular system or using a higher value when flattening the UV?

Breaking the scene into smaller parts!

Each walls separately, each floors, each ceilings, etc. You have too much stuff for 1 poor lightmap!!!

The more you separate things, the more your lightmaps are going to look good (if you also make well layed-out lightmaps).

Couldn’t agree more. In my project, I had all the walls as a single object. So, instead of separating each walls, I separated the faces which were directly exposed to lighting. By this way, we can minimize the Lightmap resolution of each objects and also get better results with lower settings.
For example, I have found following values applicable across the projects with very less degree of variance:

Static Lighting level Scale : 0.7 - 0.8
Num Indirect Lighting Bounces : 100
Indirect Lighting Quality : 5
Indirect Lighting Smoothness : 0.6 - 0.65

Most of the times I haven’t even touched BaseLightMass.ini

With regard to Unwrapping, I used steamroller but it has few problem for complex objects(I get some couldn’t access level 3 object error). For Complex objects, I unwrap manually.

With regard to v-ray quality renders, some of the users (Koola, rafareis, rebellogp) have already achieved it. You can check forum posts for some of there works.

I also started to separate the faces that are going visible to assign them a high-res lightmap, and I leave the rest of the geometry on a low-res lightmap! Best solution imo.

As a totally non-architecture kind of guy, I notice that there’s a lot of free and paid resources now for offline and realtime ArchiViz focusing on things like shader quality for the suitable render pipeline, optimised geometry, appropriate UV unwrap etc.

AFAIK unless you are dealing specifically with interior design elements that clients can directly choose, then furniture and whiteware and other “clutter”/decoration need not be too specific. If the interior design elements (eg. bathroom, sinks, sofa) are manufacturer-specific and needs to be integrated, then building a asset base of such elements will be important.

So that’s my armchair observations.

Any of you ArchiViz experts doing manufacturer-specific interior design stuff with clients?