DominantDirectionalLight + BSP Ceiling = Weird

[drmccoy20]

As you can see on the pictures below, I am having a simple room done with BSP (2048x2048x1024, hollow (i know, not good. Just for speed purposes)) I did cut a hole (128x128x16) into the ceiling and cluttered it with some random static Meshes. I did then put a DominantDirectionalLight outside of the hole to shine a little bit inside and light the room.

Now, as you can see, the walls and floor and oddly the whole room seems to be lit just like there was no ceiling at all. I did not change ANY lightmass settings, all prefs I changed on the DDL were brightness (4), color and render shafts.

Now, this is already the second time that UDK decides to act funny like that, so I wanted to throw this up here. If it's a common known issue, I didn't find it. If I'm forgetting something here, please tell me, it's slowly tearing my sanity >.<

The Walls and Room
[SHOT]http://img864.imageshack.us/img864/1244/weird01.png[/SHOT]

The Ceiling, you can see the whole a little bit. Way not big enough for such a lightning.
[SHOT]http://img832.imageshack.us/img832/6954/weird02.png[/SHOT]


All in all, UDK likes to ignore the fact of a BSP Ceiling and a DDL, since it's working if I make a ceiling with Static Meshes.

Help?^^

[Spoondog]

Does the bsp ceiling have a poly on top facing upwards? Light passes right through backfaces.

[drmccoy20]

Yes, it does. As I said, it's a HOLLOW cube that's been ADDED. Hell I even put a material on the outside of the ceiling .. still no change :/

[Photonic]

That is very odd, as a test, add a non-hollow BSP box above it to block out the light.


BSP has odd issues with shadows going through other BSP. My advice, if what I posted above works, is to make the walls separate BSP. Make sure your meshes are not pushing out of the BSP box as well...

[drmccoy20]

I'm at work at the moment, I'll try it out once I get home. I have some pillars in the room (you can see them at shot 1) which are sticking out of the bsp walls on the other side. Same for some of the ceiling structure. I don't think that this is causing the problems though.

As for your suggestion, I'm not very optimistic about that. On another map I didn ~2 weeks ago, I only added BSP floor (non hollow) and did the walls completely out of Static Meshes, then added a (non hollow) BSP ceiling above it. The map did behave exactly the same and light coming from the DDL did act as if the ceiling wasn't there at all. I ended up cluttering the ceilings on the outside with large "wall" static meshes that blocked out the light. Very amateur, but it worked.

I'm kind of buffled at this, i've never seen anything like it and it really starts to slowly drain my sanity ^^
Any further help will be appreciated

[Spoondog]

This might be too obvious, but did you rebuild lighting?

[drmccoy20]

Several times, yes. Only preview quality, but I don't think that's the cause of the phenomenon here.