Good day!
I have a complex mesh, which lightmap i cannot fix. Have done quite a bit of googling and there are still issues.
Below I also post lightmap UVs (automatic UVs from Maya without intersections were the source of UE4 lightmap):
Whatever I do: change UV layouts, increase lightmap resolution, nothing proudces clean shadows.
What could be the problem and how can it be solved?
Thank you for any answer.
Your UV’s are really bad, you need to do them properly by hand to get good results. Also keep in mind, by default UE4 will automatically generate lightmap UV’s when you import a model, so you have a third UV channel which is the one that UE4 made, don’t use that one.
Thank you:) But it is the 10th (or 100th:)) layout i am testing. It is not the best one, but, surprisingly, it produces the least artifacts. I have been trying to make UVs by hand - the results were worse than automatically generated ones.
And sure, I remember to switch between generated and custom UVs, whenever I am using custom ones.
It might just require practicing more with UV mapping. Automatic methods are terrible
I have also started thinking, could it be a shadow map problem? Here is the screenshot of the baked shadowmap from my World Settings. Could it be that its resolution is too low? My model has a lot of fine details, but it looks like they all overlayed by shadows very roughly…
Like @darthviper107 mentioned these issues are likely due to your lightmap uv’s not being optimized. Automatic mapping may be fast, but if you’re looking for good results it isn’t a viable option.
Thank you 
I have already grown to accept that) I have redone a part of of my scene’s UVs manualy. And my lightmap looks much-much better.
Yes automatic uv mapping is horrible. You have to set up channels for your uv’s our unreal will automatically make you one. You should check the uv maps and know when to ombine certain elements which doesn’t map a certain degree angle, and etc… and alot of your uv’s need relaxing at that…
Basically uv mapping is a important process and take your time to do so.
i know, i know. Learnt it hard way
don’t worry i kind of did too. I found a good tutorial. with 6 hours on the uv topic was very good
