[tec] "bouyancy problem"

[Ducimus]

Originally Posted by Kromus

Ok I give it a shot

Don't be surprised if you end up with some ahh..... side effects. Tuggin on those variables will fix sub on rails for sure, but it's much akin to being a kitten tuggin on a ball of yarn. Two biggest side effects to look out for is

- AI visual sensors changing drastically one way or another.
- surface ships randomly sinking/exploding for no apparent reason. (crash depth issue with damage zones in zones.cfg if i remember correctly)

To minimize the chance of that happening, Be gentle, don't adjust it drastically. Only as needed, and very carefully, and deliberatly.

[Kromus]

Originally Posted by Ducimus

Don't be surprised if you end up with some ahh..... side effects. Tuggin on those variables will fix sub on rails for sure, but it's much akin to being a kitten tuggin on a ball of yarn. Two biggest side effects to look out for is

- AI visual sensors changing drastically one way or another.
- surface ships randomly sinking/exploding for no apparent reason. (crash depth issue with damage zones in zones.cfg if i remember correctly)

To minimize the chance of that happening, Be gentle, don't adjust it drastically. Only as needed, and very carefully, and deliberatly.

Thx for warning and info

Yes I just tried changing original values (0.3->0.03 and 0.75->0.6) and sub was like "running through the waves" no pitch/roll anything. So definately this is the way so thx both for this. Problem seems to be those side effects now

[Ducimus]

>>no pitch/roll anything.

CG_Height in the sub's sim file. Default is 1. In previous games this was a little under or a little over 2. Here you have to be careful again or you'll have a sub doing 360's along its long axis, or end up upside down if rammed or something. One additional thing i noticed was that on deck, in rough weather and this adjusted to say 2.X.. i found myself catapuled onto the UZO as if i was standing on it. My "feet" being launched right off the conning tower deck. So, again, adjust carefully. Hope you like restarting the game alot. (insert DRM rant here).

With stock enviormental settings and waves, i found ehh 1.8 or 1.9 (i forget, but i think 1.8) to be the most i could set it before having the "catapult onto the UZO" feeling.

Hmmm.. i guess the camera doesn't move with the boat?

[vickers03]

Originally Posted by Kromus

Yes I just tried changing original values (0.3->0.03 and 0.75->0.6)

sorry but you're not looking carefully enough,
it should be 0.3->0.6 and 0.75->0.03, a big difference.

here's my modded 7a, take a close look at ALL values
and compare with sh3/GWX stuff.
http://www.filefront.com/16047457/sh...sh5_7a_test.7z

[Kromus]

Originally Posted by vickers03

sorry but you're not looking carefully enough,
it should be 0.3->0.6 and 0.75->0.03, a big difference.

here's my modded 7a, take a close look at ALL values
and compare with sh3/GWX stuff.
http://www.filefront.com/16047457/sh...sh5_7a_test.7z

Yes I noticed that it did the opposite thing :P I`ll look at your file later gotta go sleep, gn.

Edit:

http://www.filefront.com/16048001/7b_test.zip

My try with VIIB but still with original values in sim.cfg used (will be messed up if sh3 sim.cfg values used)! Now for real, cya tomorow.

[Redlance88]

so we have some idea of what values can be adjusted, and it sounds like with the right "tweaking" of some of them we might be able to get a boat that will be able to maintain a depth at all stop but beyond that depth will need progressively more forward motion to not sink to oblivion. and to me that sounds correct in terms of real world physics. so now the question becomes what are accurate values for the historical subs, and at what depth did this become a factor if at all. if that depth is beyond crush depth the point becomes moot. and nothing is needed beyond any adjustment to keep the effect from happening too soon( shallow). thoughts?

[Bilge_Rat]

just to add some real world data which may or may not have a bearing.

Normally, a submarine will trim to have a slightly positive buoyancy and will use a slight downward angle on the planes and forward motion to maintain a set depth. The theory being that if power should be lost for any reason, the sub will gently rise to the surface.

the trim for a boat is dynamic and directly influenced by the depth. Air provides buoyancy and its effect is influenced by depth. As you go deeper, air is compressed and loses its buoyancy. A boat which is positively buoyant at 50 meters will be negatively buoyant at 150 meters at the same trim since the air in the ballast tanks will be compressed letting in more water.

normally, when a boat dives from, say, 50 meters down to 150 meters, the diving officer will have to rest the trim by pumping additional air in the ballast tanks to again achieve a slight positive trim.

All these factors also explain why you sometimes hear stories about crews losing control of the depth. If the wrong buoyancy, plane angle, speed is set, the boat may easily go past the set depth before they are able to bring it back to an equilibrium.

Although in theory, it may be possible for a sub to maintain depth while motionless, it practice it would be too difficult.

of course, none of these factors have ever been properly represented in a subsim and they may not have a bearing on the discussion here.