Very nasty lightmask bug!!!

Hi all,

I found very strange bug i guess please check image and tell me what you think. Also how can report it back to epic pls ? As you can see i was doing scale test and found out very interesting thing, if you make some simple object wich is very thin for UE is very difficult to make correct lightmap for it. Using maya for it and export to FBX 2013 map is 64 of size… No matter if you do scale in Maya or UE same result always :frowning:


This is not a bug. It’s just the floor mesh’s lightmap resolution isn’t high enough.

true thx :slight_smile: ■■■■ i did not think of that at all :frowning: my bad

Just test it and it is not it!!! Used 64 object and 64 floor same resul, broken light

You don’t need to increase the shadow casting mesh’s resolution, just the floor. 64 still may not be enough res. for a surface that large.

Well i just found out that you have to keep res for floor ver low something like 8 to make shadows work nicely… Just dont get it why… What is the recommandation for res for floor and objects pls ?

BTW if i really keep res of floor very low res all works ok, just dont get why, still think this is kind of bug

Oh, i didnt know the floor was a BSP. BSP resolutions go backwards…lower res., higher quality. So, it is not a bug.

There isn’t a general lightmap res for walls and objects really. It all depends on your project, the scale of the environment and how much screen space those meshes cover. So you’ll have to figure it out in time for your own project.

Hmm yeah works backwords with BSP just tested with landscape and have same problem but dont know how to change res on that ?


Select your landscape and look at the Details panel on the right;

Lighting > Static Lighting Resolution. It is set to 1 by default. Start with 4 and go up to 12 until you get the looks you want, but the time to build lights will take a lot longer as you go higher.

Thx you helped ,me a lot :slight_smile: Not i do understand how lighting works on UE4 :smiley: