Sun Shadow Transition INI Settings

[DoubleYou]

I created these videos a while ago, and finally uploaded them to Youtube for your viewing pleasure. Most are linked on the INI guides, but I think one or two are not.
 
Skyrim.ini

Smooth sun-shadow transitions

fSunShadowUpdateTime sets the speed of sun-shadow transitions in seconds. It is recommended to be adjusted to minimize the transitions.
 
fSunUpdateThreshold sets the time between sun-shadow transitions. A value of 0.05 is equal to 1 second, so a value of 1 equals 20 seconds. Increasing this also increases the distance the shadows will move during the transition. It is recommended to be adjusted to minimize the transitions.
 
Default Sun Shadows
fSunShadowUpdateTime=1
fSunUpdateThreshold=0.5

 

STEP Tweaked Sun Shadows
fSunShadowUpdateTime=0.25
fSunUpdateThreshold=1.5

 

Other Various Tweaked Sun Shadows

fSunShadowUpdateTime=0
fSunUpdateThreshold=0

 

fSunShadowUpdateTime=1

fSunUpdateThreshold=0

 

fSunShadowUpdateTime=0

fSunUpdateThreshold=2

 

fSunShadowUpdateTime=0.5

fSunUpdateThreshold=0.05

 

fSunShadowUpdateTime=0.5

fSunUpdateThreshold=1

 

fSunShadowUpdateTime=1

fSunUpdateThreshold=1

 

fSunShadowUpdateTime=2

fSunUpdateThreshold=0.5

[Yakuza]

Hi. So I have a different setting used than what is recommended, based on what the STEP wiki provides for information on the two Sun values. And I wanted a couple questions answered since it's confusing.

 

fSunShadowUpdateTime=3 ;;Game takes 3 seconds to transition to the new shadow position

fSunUpdateThreshold=3 ;;Game takes 3*20 or 60 seconds to send the update.

 

Am I wrong in thinking this causes the game to do more work in a burst, and/or less work over time? Is the game still checking for sun/time changes every 3 seconds or whatever for 1 minute to pass in-game? Are any of the 3 below statements true?

 

- More GPU work in a burst because it has to move all shadows at once for a longer period of time.

 

- Less GPU work over time because it's not frequently changing the shadow position.

 

- Less CPU work over time because it's not constantly checking the sun time (i.e. fSunUpdateThreshold = gametick checking?)

 

 

Maybe I'm misunderstanding what these settings do/expecting more out of them. I actually enjoy 3/3 settings because shadows are more static (which I prefer but it's probably not as good as constantly moving shadows), but they also sort of shimmer like they would in real life with birch trees and such when the wind blows. And best of all, they don't drastically change in position. I was mostly hoping it helped with game performance at high shadow distances, though.

Edited November 6, 2015 by Yakuza

[Spock]

I personally really like 0.5 for both values, but I also use a reduced time scale. Your shadows seem to be affected by the lod switching bug btw (I recently posted a video by defosh369 here: https://forum.step-project.com/topic/9291-yakuza-shadows-optimized-shadow-presets-for-any-pc/?do=findComment&comment=146208).

[DoubleYou]

I do most of my shots with default values for the other settings so that they cannot possibly have an effect on my tests. That's why that bug is in there.

[Shadriss]

I've always been curious - is it possible to set these up so that the shadows are actually continuously moving, IE, simulating real time update? ANY kind of jump is jarring to me, no matter how quickly it happens, so I'd rather have a slow transition that ends just as the next one begins to make it look like one smooth continuous motion. Possible or Pipe Dream?

[Spock]

A good friend of mine explained to me what he thinks is happening (from a quick look). He said that there are shadow tracing artifacts in the way Skyrim shadows are traced, visible when the shadow moves as flickering. The sun shadow update mechanic is a hack to mask the faulty shadow tracing code. You would have to fix the code and disable the hack. He said fixing the shadow tracing might be possible with draw call interceptions, but he would have to know the possibilities of the ENB shadow shaders and find the time etc.

Edited November 20, 2015 by Spock

[DoubleYou]

See the videos. They can be continuously moving, but the timescale is so fast that it really seems odd. It feels like you're in a time-lapse video.

[elwaps]

@Yakuza

Forget about CPU load, I didn't have a single situation in four years of Skyrim where the CPU became the bottleneck.

 

I've had the 0.25/1.5 settings recommended by STEP so far but the "not moving for a while"/"moving alot at once" transitions always annoyed me. It becomes smooth when for example using 0.25/0 (inspired by your 1/0 video) - but even when using an ENB (Vividian default) the shadow isn't smooth enough to not look weird. Is there any solution to this except for going to extreme shadow resolutions? I would but I actually have to GAIN performance (thanks JK/ETaC/Verdant/CoT/ENB!) to get a well playable Skyrim in all situations.

 

https://www.youtube.com/watch?v=ObXhsBIjXNk

 

https://www.youtube.com/watch?v=g1XJpqjugYA

 

/edit
Recorded with "set timescale to 100"

Edited November 21, 2015 by elwaps

[DoubleYou]

How about this:

 

fSunShadowUpdateTime=500000000000
fSunUpdateThreshold=500000000000

 

I guarantee you will not see the sun transition   

[elwaps]

 

 

I'm currently trying to merge some AOS2 patches (that for some reason include a huge amount of sound files when merging and therefore apparently take ages to finish) followed by an approximately half hour reproccer and a one hour DynDOLOD run so I can't test for myself at the moment - but what would happen when setting both values to 0? Incredibly smooth realtime sun transitions bought with 30 instead of 17% CPU load?  :O_o:

[Spock]

Afaik CPU load is not the problem, shadow tracing artifacts are. It just doesn't look good.

[elwaps]

So all one can do is playing with 8192 shadow resolutions and buy this with 5-10fps? ^^

[DoubleYou]

It doesn't cost much fps to set to 0, but looks terrible IMHO.

[spaceoden]

I always thought the STEP recommended settings looked terrible.

The philosophy of "well it's bound to look bad so let's just get it over with quickly" does not jive with me.

 

Skyrim is such an immersive experience, and the one thing that was consistently killing immersion for me was these ridiculous sun shadow transitions.

 

My philosophy: "let's try to make it look as realistic as possible with the smallest performance sacrifice".

 

I recently tried:

SSUTime: 0.25

SSUThreshold: 0.005 (10 times per second)

 

It looked great. The visible transitions were gone, the sun was simply crawling across the sky like real life. The only shimmering I noticed was on the anti-aliased edges of stairs. A small price to pay for 0 immersion breaking transitions. For someone playing at a resolution higher than 1920x1080, that shouldn't be noticeable at all.

 

Now I'm going to try:

SSUTime: 1

SSUThreshold: 0.05 (1 second)

Edited December 29, 2017 by spaceoden

[spaceoden]

Yeah 1 to 0.05 looks very good. 10 to 0.5 should look just as good, I'll test that next. That's a digit away from the defaults. I think that must have been what beth started with. I guess they either made a math error, or perhaps they, like whoever chose the step values, didn't like how the shadows looked and sped up the transitions.