Stuck: Lighting Issue

I’m fairly new to unreal engines still.

I have a multi-level building. I just added a third floor (aka roof for the second level) and I’ve just begun getting this message: “Large actor receives a pre-shadow and will cause extreme performance hit unless bCastDynamicShadow is set to false.”

At present, it wasn’t always this way, the ceiling is pitch black.

When researching the problem, this forum as well as the unreal documentation, nothing has proven instructive or helpful toward finding a solution. The Doc’s offer " A large Actor has been set to cast shadows - this will cause extreme performance issues and should have bUseBooleanEnvironmentShadowing set to true."

I have no issue with these ceilings not casting shadows. My problem is that I can’t find where and/or how to adjust either parameter. I used the ~ to open a command line but I’m not entirely certain of the syntax to use to properly execute either of these parameters or if there is a way to see the entire code so I can search for each parameter. I also do not know which parameter is the appropriate one to use or if both need to be adjusted.

I’d really rather avoid remaking this item if it can be helped.

Thanks in advance.

It sounds like those meshes are set to Movable, which means they are using only dynamic lighting which can lower performance

Thanks for the reply,

So, the resolution would be to go to the meshes used and reset to static?

I checked every mesh related to that floor/deck and even the one beneath it - everything is set to static. The only moveable items are the doors I added.


Try and set your main light to static as well

Unfortunately, that didn’t remove the statement. I added more static lighting on that level to remove as many shadows as I can. The statement still shows up when I build the lighting. So far I’m not seeing a performance hit. I’m just trying to be proactive at a very early stage about keeping the fires to a minimum.

The resolution was to add a Lighting Importance Volume around the entire structure.