Here is a room that is closed toward the corridor. Behind the door there is a static light. The character in the room is of course dynamic.
The character receives the static light as if there was no wall or door. the static meshes have their “cast shadow” flags all set and lighting is rebuilt.
Any idea what I may be doing wrong?
Thanks
Ok, I was working on this all day long. In the hope that this may be helpful for others, here is what I found.
The problem is not the light source directly, rather the indirect light caches created by the ligthmass importance volume.
The light cache points are created at certain locations and take into account only the light that reached them. The corridors stopping the light from reaching the cache points, all is how it should be. the cache points in the room above are nearly black since the walls don’t allow light to reach them.
The problem comes from the cache points that are placed in the corridor on the other wall or in the rooms below and above. These points are much brighter since they can be reached by a lightsource. Now when these points are used to light a character indirectly, the walls are no more obstacles.
In other words: Direct light from a lightsource is blocked by a wall and can not reach the character, indirect light from a light cache point is NOT blocked by a wall and can reach the character.
This means that indirect lighting is basically useless in a tight environment like this house with small corridors.
If anybody from Epic reads this: Could this be made a feature request?
This is to be expected since movable actors are lit by the cache, as you noticed.
To get better results, you need to either increase the number of samples placed by setting this in World Settings > Lightmass > Volume Samples Placement.
Alternatively, you could use a Character Lighting Volume in places where you need more accurate ILC sample placement but don’t want it to affect the entirety of the level.
Use the Show > Visualize > Volume Lighting Samples see how the ILC samples are placed and to help troubleshoot your issues.
You also have the option for your movable actors to set whether they use Indirect Lighting Cache Quality of Point, Volume, and Off in the Details Panel as well.