LightLeaked through walls & shadows got blurred after distance!

Hello ,
I searched a lot about these two problems but i can’t get a proper solution .
about the light leaked it’s ok when i am near the wall … once i got away the light start leaking
think the two problems might have a relation
here are images from what happend

and here is the second problem appear more in the next two images
here you can find the shadows go well

and here the shadows start to leave the object and get blurry

the main light i am use … the one the blank project BPLightstudio ( sun and hdri )


I’m not sure because I do not see your scene completely, but it looks like Ligntmaps has a low resolution or not build, or builded with low quality.
Read this thread, i think this help you

Hi Ahmed,

Looking at your scene there are a couple of things to note.

First being that I see you’re using the BP_LightStage. This has been setup in a very specific way that normally lighting would not be setup for a normal level, which I’ll go into in just a moment.

The problem you’re seeing with the light bleed is because this is using a Movable (Dynamic) Light. There are limitations with the cascaded shadow maps that it produces because it needs to have a decent performance. At certain distances this shadow is going to fade out and not be visible anymore. This is common in games using Dynamic lighting for shadows (ie. GTA V, Skyrim, and Fallout).

The Blueprint has some settings that are made available to adjust the light though. You can increase the Shadow Distance to 20000 instead of 10000. Anything over that amount and you’ll see more errors.

Secondly, if you were to setup a new default scene you’ll have access to your Directional light. You can choose its mobility here (Movable, Static, Stationary). If you want to use movable lighting only you can choose to do so. The settings in this are going to be more extensive than what was made available in the BP_LightStage. You can control the shadow Bias and Shadow Sharpen Filter to help reduce any light leaking. You can take a look at one of my lighting Wiki tutorials here to help understand this method a little more. Again, this isn’t going to always give the best results, simply because dynamic lighting has its limitations.

In a new scene if you decide not to use Movable lighting you can use a combination of the two by using a stationary light. This will give you baked shadows at a distance to help not have any shadow bleed and when you get close it will only use dynamic shadows only.

I hope this has been helpful and if you have any questions feel free to ask. :slight_smile:


Hi Tim,
thanks a lot for your replay … almost the leaking is done now but still have another problem …
it’s about the shadowing … seems that i got multiple levels of shadows with a trigger by the camera distance … i wanted to keep the maximum shadow quality you know …
all i need from UE4 a video … i am with VFX background :wink:

I’ve not had time to get this up yet and I’ve got a little bit more to add to this, but here is some updated information for using Dynamic lighting with Cascaded Shadows . These only apply to Directional Dynamic lights and not to point or spot lights. This can help you understand how to get more refined shadows that are not solely by adjusting the shadow bias or the filter sharpen.

Hopefully that doc will help you get the shadow quality you want from the directional light. If you have any questions feel free to post any screenshots along with a description of what seems off and I can offer some help. :slight_smile:

HI Tim

In this section:
How do I generate lightmap UVs in the editor?

I cannot find that L0DO tab anywhere on the right-side tab when I click on a object. Is there a an interface change that I am not aware of?


This is covered in our Wiki Lighting Troubleshooting and Tips guide. Take a look and let me know if you have any questions.