Ok, so it seems that a mod (Thieves Guild Hideout Redone) is doing something to the lighting in the Ragged Flagon, which is causing certain lights to come on and off depending on how you move your camera.

Below is an example using the ceiling of the Flagon, but it happens in the vendor alcoves and the water surface as well.

http://imgur.com/E1Sbjvi
http://imgur.com/a3axQJ4

What I'm looking for is what could be causing this issue, and how would I fix it? I'm assuming that this is something that has been encountered before, whether in this specific circumstances or not, and can thus be fixed. This issue doesn't exist in the Cistern part of the Ragged Flagon, so its something going on in this specific cell.

Are you using any lighting mods? If so maybe they are overwriting the mods changes.

I do not use a lighting mod and as I said, this happens only in this one cell.

Maybe the mod author was using one and made changes so that it would work with that. Maybe the mod author was using an ENB and made adjustments to work with that.

I do not use the mod. I have never set foot in the thieves den since I have never played a thieve and even if I did that character would likely be a lone wolf thieve.

Maybe it is a dirty edit on the mod.

Have you checked the mod pages discussion section to see if other people are having the issue.

Yes other people have the issue

No there are no solutions

There are no edits to lights in the cell, or to lighting objects in general (the only ones in the mod are new lights added for a new cell they put in, which works fine)

There are no dirty edits.

Sounds like too many lights are affecting some meshes. What happens when you check the http://i.imgbox.com/1zhxRRqi.png?

Edit: This was written for GECK but it's still applicable and informative: http://geck.gamesas.com/index.php?title=gamesas_Tutorial_Lighting#Performance_and_Optimization

I swear I read an equivalent page on the CK wiki but I couldn't find it.

Ok thats what I needed to know! I'll check it out and see whats up. Thanks!

1) then its an issue with the mod

2) there are always solutions but not always easy ones

3) There are new lights added, 02005C78 - DefaultCandleLight01NS [LIGH:00088238] for one.

1) Well of course its an issue with the mod

2) Yes, thats the point

3) Thats only used, AFAIKT, in the new cell the mod adds, which doesn't have this issue.

At any rate, I followed Antares' advice and L O L

http://i.imgur.com/RmNCYQz.png

One thing to keep in mind is that the render window doesn't know the "enable state" of those lights. Quite often interiors like guilds and player homes have different lights enabled at different times.

If you're able to group these lights together I seem to remember that hiding them using the "1" key will update the render window debug. This is of particular note in the Ragged Flagon where the furnishings in those alcoves are enabled are completing various quests/objectives.

Hope this helps

I checked the Vanilla, USLEEP and USLEEP + TGHR states of the Flagon, and TGHR adds a bunch of lights.

I'm going to make a patch to remove some that were added and see what it looks like, and then adjust from there.

But I only really noticed the problem when I got to the last upgrade level for the Flagon, so I'm betting the mod author added lights to brighten the place up, and it was just too much.

I think the limit is around 4-5 lights (I can't remember but it's not very many) on a mesh including hand-held torches or candlelight spell effects. The range is often much large than the light's radius suggests ("L" hotkey), the debug shader is more reliable (and in-game observations ofc )

It sounds like you're on top of things now. Good luck

4 per mesh, and only 4 shadow casting lights per cell.

How can you tell which lights cast shadows?

I have been following this interesting thread. I wonder if this is the issue I have with lighting in inns. I have seen it in some of the inns, particularly the Frostfruit Inn in Rorikstead, but I have seen it in a couple other inns as well. During certain times of day, the skylight flicks off when you stand in certain places in the room, particularly the corner on the far right (as you enter the room) over behind the bard and next to the end of the fireplace. I've had it happen in the vanilla game with only USLEEP, SkyUI and Alternate start. I wonder if Beth put too many light sources in the inns?

In general, the Non-Shadow ones have an NS suffix. Otherwise you'd have to look at the type on the form - Omnidirectionals don't, all the other types do.

Edit: and the "4 lights" rules seem to be a bit inaccurate. I suspect there are some other factors that complicate it. I've seen the same issues in unmodded cells.

I think you can circumvent the 4 shadow casting lights limit with occlusion (roombounds/portals) but I've never needed to so I could be wrong. I've often found that with shadow lights less is more. Having few shadow casters makes them all the more impactful in my opinion.

You can usually tell which lights are shadow casters from the naming convention. As ghastley said non-shadow lights are often denoted with an NS suffix. You can also tell by looking at http://i.imgbox.com/FvlWOzbC.png.

Thanks for that. I'm working on something right now and was wondering what kept causing flicker. I inadvertently fixed it by removing shadows on some lights, but now I know specifically what to avoid. I wonder if SE will have the same limitation.