So after being busy busy on making a snow replacement mod (Which is pretty much done but my perfectionism isn't letting me :P) I've been researching this: http://www.modthesims.info/showthread.php?t=631406

We all know, the ugly seams at night when it's snowing. Now upon my research i found out:

• Snow is actually a visual effect
• Lots lighting isn't "World" generated but done inside the bounding box of the lot (if that makes any sense?)
• Upon the moment the snow is getting more and more visible till the in-game script decides it gets to the "light" snow level, the lot turns completely dark as well as other lights on the lot (See porch light in the help thread I made)
• Looking at trailers, reviews, etc. This has always been an issue.

Now I'm wondering, I feel like getting more into lots lighting could potentially fix this issue but I can't find anywhere where the lot lighting could actually be. I get the feeling it's done within the engine given all the referenecs but if you guys have ever seen a LITE file or anything lighting-related for lots I'd love to know

Orr your own lead onto the issue. Unfortunately, it's not in the precomp files.

Well there is this INI file in one of the DeltaBuilds, I think DeltaBuild0, that controls a variety of values related to the game's ambient occlusion (which it definitely does have, just not in the obvious sense). It claims to deal with wall and roof shading, but it seems that anything with geometry is technically capable of casting shadows and being used for AO calculations. There's a fair chance playing with these values may have a noticeable effect on the world as well as individual lots. I'd have to play with it myself to know for sure but it definitely looks interesting.

It's instance 0x08326707B4EB37B5, with a file header listing its name as "Tunable Parameters Related to Ambient Occlusion on walls and roofs".

Lot lighting is weird in general.

- They completely broke inter-floor lighting with World Adventures (presumably with the introduction of basements), and there's some general inconsistencies in terms of which lights spill over off-lot and which don't. Though it was probably understandably done to make the game more efficient (so small lights don't have an effect), they overdid it, and even mid-sized outdoor lights don't spill over.
- The large streetlights (i.e. the Apology Streetlamp) seem to work in off-lot lighting.
- Off-lot lights work 100% in terms of inter-floor lighting and light spill over. Very strange, and the lighting is actually advanced enough that on the same lot, a building can cast shadows onto itself.
- Because of that, I mostly rely on off-lot lighting in terms of large-scale lighting in my worlds. The only large on-lot lighting I use is for large open spaces where the inter-floor lighting issue doesn't show up, and for small-scale lighting attached to buildings.
- That blue tint in unlit rooms seems to be hard-coded?
- Shadows also seem to be hard-coded?

I think snow is just an effect that offsets the terrain.

@AGuyCalledPi

I tried tinkering with those effects, and like most settings in TS3, I don't think it has much of an effect. It would be really nice if there settings that worked in bumping up the darkness, so that buildings don't seem so flat at times. TS3 also has a simplistic faked ambient occlusion which I think only affects the walls near the ground and under roofs.

With the AO shadowing you'll end up with something like this:



(see dark roofing and ground-up walls getting darker)

It doesn't seem to affect snow however. The way snow works is actually non-shadow based. Visual effects obviously don't do shadows unless it's a mesh, which would then be the normals as well as 'sun-directed' rendered... well shadows that cast onto the mesh. The sims 3 however uses 3 different shadows: Sun-shadows, drop shadows and sun-engine-rendered shadows. So yep most of it is hard-coded shadows (which engines these days would not have any problem with whatsoever) but for ts3's engine that seems to be the case.



ah yes! the large streetlights seem to be really focused on off-lot lighting indeed. That's partially because they use "World light" rather than "Point" light like all the other lamps. It also has some other clarifications inside the scripting of the streetlamps that don't have much to do with casting the lights but it certainly renders a bit differently.

Now, it seems though that streetlamps and lot seams and all that is perfectly fine when the regular terrain is showing up, it's just that when there's snow, and you place a lamp onto it, the light source seems to be coming from down rather than... well, up like the world streetlights.

Does anyone in that regard know if there are 2 different streetlights? one world one and one buy mode version of the same street light?

I have noticed that street lights, as a whole, are fairly overpowered and will easily light up a 10-15 tile area especially near the edges of lots. Now that's probably intentional but it's very ugly light and it could probably be made to work better.
Either way the AO seems kind of strange and rudimentary, and I'm not surprised it's that easy to make it go haywire. Does anyone know if this is also what causes the bug where entire ceilings will sometimes turn pitch black, despite receiving plenty of natural light?

I find that setting streetlights to a dim intensity usually works pretty well.

Ceilings are entirely unpredictable at a certain point IMO, if your building is complex, uses CFE, and is large.

I usually turn them off entirely and use CC invisible lights instead.