High Tides Along Heterocera Coast

[Rufferta]

I was on the North Coast Road at the intersection of Tiger, Togata, and Moma, and noticed this.  Is there a Linden Department that takes care of this?

 

[Sylvia Tamalyn]

That's interesting... if you look at that spot from either end of the tunnel (Togata and Tiger), it looks fine. If you go up to the lighthouse area in Moma, you see it as shown in the photo. I remember @Abnor Moletalking about the split level effect of water heights somewhere in the Linden Homes threads, but I don't recall specifics. 

It may also have something to do with the fact that this off-sim object sits where four regions meet. That always results in randomness. 

[animats]

Now that's interesting. It's an LL mainland land design error.

Waterfall between Momo and Togata. Those water levels are different on purpose.

• Togota: water height 20m.
• Moma: water height 35m.
• Tiger: water height 20m.
• Off-world water west of Tiger and north of Togata, and northwest of Moma: each sim uses its own water height.

This has to have existed for a long time. It must have been noticed, especially since there's a Linden lighthouse right at the corner, positioned to view this.

 

Edited March 24, 2021 by animats

[animats]

To fix this, a new Linden water sim is needed north of Togota and west of Tiger. Then the water area gets its own water height. Also, that would let you sail along that cost. Right now, you can't; there's no boatable water at that corner.                                                                                                                                        

[Rabid Cheetah]

 

[Rabid Cheetah]

 

[Eirynne Sieyes]

Maybe it was repaired by the time I got there; I did not see a glitch at the North Coast Road intersection falls. Nevertheless, the water level height difference at the at the Tiger/Togata/Moma intersection was 20 meters. Sutherland Dam, pictured below, with a 60 meter water level difference is one of my favorites.    

We've seen gliches in Belli as well. To prevent its occurrence in the Log section, the Lindens raised the water level by 20 meters, thus giving up the ability to sail continuously from any of Logland's rivers to other sections of the continent. Perhaps the Belli glitches were more reliable?

I love how water level changes look with dams and falls. I wonder why sometimes a water level change glitches and at other times it doesn't? 

 

Edited March 25, 2021 by Eirynne Sieyes
error

[animats]

Multiple water levels meeting at a corner that includes a world edge causes the original problem here. The correct water level for off-sim water is then ambiguous. LL can fix it by adding an open space water sim at that corner.

[Eirynne Sieyes]

14 minutes ago, animats said:

Multiple water levels meeting at a corner that includes a world edge causes the original problem here. The correct water level for off-sim water is then ambiguous. LL can fix it by adding an open space water sim at that corner.

Oh good! More sailable water!

But, I doubt that was the Belli problem. I don't think they would raise the water level throughout a whole theme since glitches would occur in parts of the world that were not necessarily bordered by edges. Probably two different issues altogether.

[Eowyn Southmoor]

This bug has existed for years. SL's default water level is 20m, and the way the grid works, it stretches out to infinity, even into void areas - regardless of whether it's mainland or private regions. Without this effect, which basically gives us a horizon, (even if u cant actually reach it), i'm not sure what we'd see at the edge of each region, maybe sheer blackness lol

Anyway, the problem occurs because that default water layer exists everywhere, even in regions that don't use a default water level - for example parts of Bellisseria, the Linden Memorial in Corsica, the high water in southern Sansara.  So what happens is that if you are in a region with the "high" or non-default water level, you'll see this water layer, but you'll also see the default water layer too. That gives you that odd double-layer effect.

However, If you stand in a region that ONLY has default water, and you look across into a region with "high" water, then you don't see the effect.

 

Take a look at the follow pics taken from Sutherland dam in Sansara - the first pic I am in the high water region, looking across to the default water region - you can see the double effect clearly.

In the second pic I am hovering in the default water region, but still cammed back so I can still see the high water - but because I am not actually in the high water region, I don't see the double layer effect.

If you visit the Linden Memorial regions in Northern Corsica you'll see the effect in another way, because the default water layer @ 20m there is actually the high level, and the central lake there is lowered by several metres.

 

 

Edited March 26, 2021 by Eowyn Southmoor
typos

[animats]

Now that's interesting. I'd thought you'd only see that at the edge of the world. But Sutherland is nowhere near the edge.

 

[Qie Niangao]

3 hours ago, Eowyn Southmoor said:

This bug has existed for years. SL's default water level is 20m, and the way the grid works, it stretches out to infinity, even into void areas - regardless of whether it's mainland or private regions. Without this effect, which basically gives us a horizon, (even if u cant actually reach it), i'm not sure what we'd see at the edge of each region, maybe sheer blackness lol

Anyway, the problem occurs because that default water layer exists everywhere, even in regions that don't use a default water level - for example parts of Bellisseria, the Linden Memorial in Corsica, the high water in southern Sansara.  So what happens is that if you are in a region with the "high" or non-default water level, you'll see this water layer, but you'll also see the default water layer too. That gives you that odd double-layer effect.

Maybe I'm saying the same thing here, not sure. Standing in Wakeley looking out toward Sutherland and beyond, it appears to me that the viewer simply assumes that the whole grid defaults to the water level where the avatar is located, except for immediate neighboring regions (Sutherland) which it renders with its different (true default 20m) water level. So the "double layer" is that gap between Sutherland's 20m level and the more remote, non-adjacent regions that the viewer assumes have the avatar-hosting region's (Wakeley's) water level.

Another "double layer" viewer oddity at this spot is that even looking into neighboring Sutherland, it applies the underwater lighting effect when the cam moves below Wakeley's water level... so camming over to the bridge, it can look like either of these two views, depending on whether the cam position is just above or just below that higher water level:

 

[Eirynne Sieyes]

On 3/26/2021 at 1:13 AM, Eowyn Southmoor said:

Anyway, the problem occurs because that default water layer exists everywhere, even in regions that don't use a default water level - for example parts of Bellisseria, the Linden Memorial in Corsica, the high water in southern Sansara.  So what happens is that if you are in a region with the "high" or non-default water level, you'll see this water layer, but you'll also see the default water layer too. That gives you that odd double-layer effect.

However, If you stand in a region that ONLY has default water, and you look across into a region with "high" water, then you don't see the effect.

 

 

@Eowyn Southmoor, that the default 20-meter water is always there is the key! I've been reading about this issue for roughly two years, and I have never heard it said this way. Now it makes sense.  Thank you for this. 

[SarahKB7 Koskinen]

@Rufferta, @Sylvia Tamalyn

Hi all.

This weird water phenomenon, which I call "The Tiger Tunnel Corner" is one of my biggest annoyances about the entire Second Life grid.

Because I like to sailing boats and accomplishing bucket lists of things to see and do in SL, ths particular Tiger region of Heterocera Atoll is very annoying to me.  Tiger does not have a navigable coastline. Tiger is completely impassable and therefore it's impossible for any type of boat to complete a full circumnavigation of the Heterocera Atoll continent. However, all other coastal regions on Heterocera Atoll continent ARE navigable and passable, as I've been through all the others by boat.

The Moles and Lindens are aware of The Tiger Tunnel Corner's problems, as I've tried (in vain) to highlight Tiger's problems. According to Garden Mole (in 2019), there had been no navigable boat channel at Tiger since its initial creation in 2008.

The reason for the strange water level and no boat channel in the Tiger region, is due to the watertable height being the same as another neighbouring region, which contains a tall waterfall - which has a different water table level to the standard 20 metres of sea level height in Second Life. 

This unusual waterfall water level continues in regions towards the coast - including Tiger, which is why the continent's perimeter road passes through Tiger inside a flooded road tunnel (!). This might be a very unique place in SL where one can walk from "dry" land at either end of a tunnel and while in the tunnel, swim through it, then emerging back out onto a dry road!

Adding an additional new coastal sim to the west of Tiger might be the quick reactionary fix and a bypass to this strange place, however, there is another problem....

Relating  to and affecting Tiger's problem is a nearby offshore private island region named Regalis (just to the north-west of Tiger) is now too close to the coastline of Heterocera. Garden Mole explained to me (in 2019) that a one region null/void seperation gap MUST exist between private island sims such as Regalis and Tiger, just like in all coastal mainland regions. Adding a new region between Regalis and Tiger is therefore not an option.

However, I do think that there actually is a very easy "fix" to this problem, although potentially expensive or disruptive to the owner of Regalis region. I would suggest that Second Life should/could offer to move Regalis somewhere else on the grid relatively nearby to allow a new water region to be placed beside Tiger, while maintaining the null/void region seperation gap between mainland and private island regions.

I also previously sent a  notecard to @Patch Linden in November 2019 to highlight the Tiger Tunnel Corner's  issues and my fix ideas. Patch Linden did initially reply that it would "not be fixed", but after some nagging (from me!) he actually then replied again in November 2019 that the Tiger coastal problem would be put on the list of things to do in the next "two quarters" (six months after November 2019).

Sadly a fix has still never been undertaken. In 2021, I've kind of given up at this point, and treat Tiger as a curious unique oddity,. But whenever I do occasionally bump into Patch around SL, or see him live in a Lab Gab video stream, I do like to remind him on his "promise" to fix Tiger....

Edited April 6, 2021 by SarahKB7 Koskinen

[Patch Linden]

We did go look at this, and we decided this will not be fixed anytime soon.   Adding regions along here will only move the issue further out and that would just be a costly band aid to a problem that needs to be solved another way which has not presented itself as of yet. 

[Qie Niangao]

9 minutes ago, Patch Linden said:

We did go look at this, and we decided this will not be fixed anytime soon.   Adding regions along here will only move the issue further out and that would just be a costly band aid to a problem that needs to be solved another way which has not presented itself as of yet. 

I think it depends what problem is to be solved. The ability to circumnavigate the Atoll needs one Linden water Homestead and maybe some accommodation from the diagonally adjacent private island.

The "high tides" problem, as I understand it, is really a viewer issue, needing a little more sophistication about what to assume is water height in non-adjacent void: Instead of extrapolating he water height of the agent's current region, use the height of regions directly (not diagonally) adjacent that void.

[Whirly Fizzle]

3 hours ago, Qie Niangao said:

The "high tides" problem, as I understand it, is really a viewer issue, needing a little more sophistication about what to assume is water height in non-adjacent void: Instead of extrapolating he water height of the agent's current region, use the height of regions directly (not diagonally) adjacent that void.

This is not an easy problem to solve unfortunately.
The "high tides" bug described on this thread has been fixed & reverted several times because the fix causes all standalone regions that use a non-default water height to have broken water rendering, which causes even more screams then the current behaviour described here.

See https://jira.secondlife.com/browse/VWR-29065 & all the linked issues.

[Qie Niangao]

On 4/6/2021 at 3:18 PM, Whirly Fizzle said:

This is not an easy problem to solve unfortunately.

Perhaps, but the comments in that jira seem pretty simplistic, and I really don't think it would be that difficult to make the viewer "guess" better than it does now. Of course it's wrong to assume all void regions have a 20m water height, but so it's also wrong to extrapolate the current (avatar-hosting) region's water height when the viewer is already displaying a different water height for regions that actually share a border with a region of unknown height (void or otherwise).

To start, as I showed above, viewers don't render lighting consistent with the known water height of an adjacent non-void region, instead basing underwater lighting on cam position relative to the current region's water height, despite rendering the water at the correct height for that adjacent region. That's just a bug, maybe a separate jira, but might best be worked at the same time as the larger problem of rendering water height.

That larger problem seems rooted in the viewer extrapolating the current region's water height to void and non-void regions to infinity, even those with borders common only to regions it correctly renders with a different water height than the current region. That's surely a handy simplification but as we've seen, it often has absurd results.

What I didn't appreciate until now is just how wacky those results can be. Standing in Wakeley and moving the cam around some adjacent regions, I see some rendered with water at both the (incorrectly) extrapolated current region level and the correct level for that region. That is, those regions are rendered with two stacked layers of water for the same geography, a la:

I suppose we have to allow the viewer to render even non-void region water at some "guessed" level until it comes to know the actual level when the cam has moved around more, but then rendering both levels just isn't a tolerable simplification.

On the plus side, this proves that we're already letting water render differently as the cam moves around and the viewer gets more information about regions in the scene (it just does a really bad job of it).

What I intended to propose was that the "guessed" water height for any patch of geography be based on the known height on adjacent (border-sharing) regions. In the case of a standalone island, that's simple: there's only one region with a known water height, so extrapolate from that to infinity, same as now. If the viewer knows regions with different water heights, don't extrapolate from the current region toward diagonally touching regions when there's height data from a region adjacent to (sharing a border with) the unknown or void region. If that unknown/void region shares borders with multiple regions known to have different heights (possible, but may never really happen?), "guess" perhaps by vote, maybe breaking ties by favoring the current region height iff that's the height of a region adjacent the unknown, or favor 20m if that's one of the known adjacent heights, or give up and draw straws which can't be worse than what it's doing now.

[Rabid Cheetah]

Why get rid if it?  It's a cool effect.  For those who live there, and are bugged by it, you're missing the point:  It makes your land very unique, ergo very valuable, therefore if you don't like it you'd be better off selling it and moving than trying to get rid of the feature.

[SarahKB7 Koskinen]

The Tiger Tunnel could become SL's first ever drive-through salt-water car wash! 😜

Edited April 11, 2021 by SarahKB7 Koskinen