Visible underwater

Binary101 · 03-05-08, 04:18 AM

I dont have SH4, i like that the water is much more transprent, but i was just wondering i've seen some arial photographs of submarines at periscope depth and was wondering under what conditions are submarines visible underwater and at what depth will they not be visible, also were there any uboats sunk becuase they were spotted and tracked even underwater and can this be implemented into the game?

Ducimus · 03-05-08, 05:25 AM

Quote:

sunk becuase they were spotted and tracked even underwater and can this be implemented into the game?

Ive recieved quite a number of complaints having modded the game to do just that. :rotfl:

DavyJonesFootlocker · 03-05-08, 06:59 AM

It's a bit unrealistic to me. If you're in clear, shallow waters maybe. Then there's light reflection/refraction from altitude to consider. Also visiblity- fog, etc. I placed a contract out on Duci for that.

:rotfl: Just kidding!

Torplexed · 03-05-08, 08:08 AM

It wasn't uncommon in the Mediterranean and I imagine water conditions in the shallow South China Sea were similar. Gonna have to train my flak gunners to fight in scuba gear.

You should be safe in the deeper blue ocean tho.

seafarer · 03-05-08, 11:40 AM

The open Pacific Ocean waters are remarkable clear. You can easily see objects several tens of feet below the surface on a sunny day, so I have no trouble imagining that a conning tower sitting a few feet below the surface would be clearly visible from above (remember periscope depth on the guage is keel depth).

And, while I cannot find it right now, one of the US Navy web pages has pics of a Los Angeles class boat at periscope depth taken from a supply helicopter coming to rendevous with them - you can clearly see the whole boat in detail below the surface (the pic was obviously taken on a nice clear sunny day, during some NATO exercise if I remember it correctly).

DavyJonesFootlocker · 03-05-08, 11:57 AM

Yes, but that's just a selective case. What about in bad weather conditions and night? Unless the pilots got night vision goggles it's next to impossible unless the plane is flown a few feet and 4 mph from the surface, directly above the sub.

Type941 · 03-05-08, 12:03 PM

Looks pretty visible to me.

The USS Chicago, a Los Angeles-class attack submarine, glides along
at periscope depth in the western Pacific Ocean off the coast of Malaysia.

DavyJonesFootlocker · 03-05-08, 12:11 PM

No. I meant that yes, in those conditions it can be seen, but what about less favorable conditions. Remember a helicopter took that one. A plane flying at 300 mph or more may not pick it up.

Digital_Trucker · 03-05-08, 12:25 PM

Quote:

Originally Posted by Type941

Looks pretty visible to me.

<pic snipped to save bandwidth>

The USS Chicago, a Los Angeles-class attack submarine, glides along
at periscope depth in the western Pacific Ocean off the coast of Malaysia.

From what type of craft, at what altitude, at what relative speed to the sub and with what photographic equipment was that photo taken? Pictures don't always tell the story.

The fact that it's leaving a bit of a wake would help spotting, but notice that the angle of the shot is almost directly down on top of the sub in smooth water. Add a bit of an angle (so that more light is reflected off of the waters surface) and a bit more chop to the water (so that more light is refracted both on its way to the sub and its way back) and the sub would not be as visible.

The real problem is modelling (in game) a sensor that can duplicate (within reason) the human eye and brain's ability to detect an object underwater. The games visual sensors don't see underwater (unless you use a variable designed for something else to fool the sensor into seeing an underwater object, in which case you end up with a completely uncontrollable "x-ray vision" that is impervious to light/sea/depth conditions). So far, other sensors haven't worked either (yet).

Ducimus · 03-05-08, 12:48 PM

The short of it its, in terms of undewater visual detection, you can control the RADIUS in which it is possible, just not the depth.

So by virtue of lowing a varible (exact name illudes me at the moment, short on sleep, groggy, still on 1st cup of coffee), you can make this detectioin radius larger. By raising this number, you can make the detection radius smaller.

Detection radius is important, because your giving the plane TIME to see you. For detection to occur, the AI must see X amount of your sub, for Y time. Since planes travel so fast, they can zip right though this radius before they can regester a sighting. So you can only make the detection radius so small. I think its around 3,000 meters is what i have it at.

The stop gap, was adding "Thermal Layer Signal Attenuation=5.0" to the visual sensor in the sim.cfg. At least, its hopped that works in stopping deep detection, if your below a layer.

These are the limitations imposed by the agme engine. When you make the game do something it wasnt orgianlly intended to do, its not going to work perfectly. But it works well enough, and the positive aspects to gameplay, far outweigh the occasional "WTF".

MONOLITH · 03-05-08, 01:50 PM

You guys actually had a good discussion on this quite awhile ago, including some good pictures/diagrams of the radius issue. Wish I could find those right now...

Question Ducimus...

I assume the radius prevents you from being spotted, when you dive to a depth that puts the top of the radius underwater, yes? And can you say, in TM, about what that depth is, or do other factors complicate that being a simple answer?

Major Johnson · 03-05-08, 02:03 PM

I would say that in real life the weather plays a big part of this equation. On a clear day and calm seas, I wouldn't be surprised to hear that a sub is visible down to 100 ft. In bad weather, ie, rain, chances are there's not going to be planes flying anyway. Another point was made about how high the plane is flying. Another good point, but for the sake of this game, I would say every plane is flying at a height normal for looking for subs. No point in having high level bombers. Also the cruising speed of most sub hunting planes wasn't 300 mph, it was normally around 200 or below. The 300 mph range is normally getting close to the top speed of the craft flying level. I recall seeing photographs of Uboats that were under the surface, taken by our own WW2 anti sub patrols. Many of those were taken by slow/low flying blimps, but there were also personal craft used for ASW as well. So I have no problem with planes being able to see a sub at periscope depth during ideal conditions.

On a side note, wasn't the Union ironclad "Monitor" found by a plane?? And I believe it was in 100 ft or so of water.

capthelm · 03-05-08, 02:49 PM

Quote:

Originally Posted by Type941

Looks pretty visible to me.

The USS Chicago, a Los Angeles-class attack submarine, glides along
at periscope depth in the western Pacific Ocean off the coast of Malaysia.

sh4 models the ocean perfect imo..

Ducimus · 03-05-08, 04:51 PM

Quote:

I assume the radius prevents you from being spotted, when you dive to a depth that puts the top of the radius underwater, yes? And can you say, in TM, about what that depth is, or do other factors complicate that being a simple answer?

Your aspect to the approaching plane, Sea state, light factor, and fog always complicate things from a simple answer. Sometimes they'll fly right by and not see you, other times they see you all too well.

Binary101 · 03-06-08, 02:08 AM

Thanks for the replys, I dont know much about game modding, but as you guys said under the right conditions, ie clear weather, say from 11am to 3pm and at what places on the map the uboats will be detectable at periscope depth, is there something in game that could monitor all these? graphicly you can see the uboats already underwater why so why cant enemy planes and would this be good in game?

03-05-08, 04:18 AM	#1
Binary101 Swabbie Join Date: Oct 2007 Posts: 11 Downloads: 125 Uploads: 0	Visible underwater I dont have SH4, i like that the water is much more transprent, but i was just wondering i've seen some arial photographs of submarines at periscope depth and was wondering under what conditions are submarines visible underwater and at what depth will they not be visible, also were there any uboats sunk becuase they were spotted and tracked even underwater and can this be implemented into the game?

03-05-08, 06:59 AM	#3
DavyJonesFootlocker The Old Man Join Date: Dec 2007 Location: Stink Drunk in Trinidad Posts: 1,572 Downloads: 138 Uploads: 0	It's a bit unrealistic to me. If you're in clear, shallow waters maybe. Then there's light reflection/refraction from altitude to consider. Also visiblity- fog, etc. I placed a contract out on Duci for that.:rotfl: Just kidding! __________________ "Silence means death. Stand on your feet. Inner fear your worst enemy."- Sepultura. My Silent Hunter 5 mantra is this......"Torpedo missed, sir!" A P-400 is a P-40 with a Zero after it. A proud member of the Wikipedia Haters Club

03-05-08, 08:08 AM	#4
Torplexed Let's Sink Sumptin' ! Join Date: Dec 2001 Location: Seattle, WA Posts: 5,823 Downloads: 43 Uploads: 0	It wasn't uncommon in the Mediterranean and I imagine water conditions in the shallow South China Sea were similar. Gonna have to train my flak gunners to fight in scuba gear. You should be safe in the deeper blue ocean tho. __________________ --Mobilis in Mobili--

03-05-08, 11:40 AM	#5
seafarer Commodore Join Date: Feb 2005 Posts: 622 Downloads: 0 Uploads: 0	The open Pacific Ocean waters are remarkable clear. You can easily see objects several tens of feet below the surface on a sunny day, so I have no trouble imagining that a conning tower sitting a few feet below the surface would be clearly visible from above (remember periscope depth on the guage is keel depth). And, while I cannot find it right now, one of the US Navy web pages has pics of a Los Angeles class boat at periscope depth taken from a supply helicopter coming to rendevous with them - you can clearly see the whole boat in detail below the surface (the pic was obviously taken on a nice clear sunny day, during some NATO exercise if I remember it correctly). __________________ My Father's ship, HMCS Waskesiu (K330), sank U257 on 02/24/1944 running SHIII-1.4 with GWX2.1 and SHIV-1.5 with TMO/RSRDC/PE3.3 under MS Vista Home Premium 32-bit SP1 ACER AMD Athlon 64x2 4800+, 4GB DDR2 RAM, 400GB SATA HD Antec TruePower Trio 650watt PSU BFG GeForce 8800GT/OC 512MB VRAM, Samsung 216BW widescreen (1680x1050) LCD

03-05-08, 11:57 AM	#6
DavyJonesFootlocker The Old Man Join Date: Dec 2007 Location: Stink Drunk in Trinidad Posts: 1,572 Downloads: 138 Uploads: 0	Yes, but that's just a selective case. What about in bad weather conditions and night? Unless the pilots got night vision goggles it's next to impossible unless the plane is flown a few feet and 4 mph from the surface, directly above the sub. __________________ "Silence means death. Stand on your feet. Inner fear your worst enemy."- Sepultura. My Silent Hunter 5 mantra is this......"Torpedo missed, sir!" A P-400 is a P-40 with a Zero after it. A proud member of the Wikipedia Haters Club

03-05-08, 12:03 PM	#7
Type941 Ace of the Deep Join Date: May 2005 Location: U-52 Posts: 1,270 Downloads: 2 Uploads: 0	Looks pretty visible to me. The USS Chicago, a Los Angeles-class attack submarine, glides along at periscope depth in the western Pacific Ocean off the coast of Malaysia. __________________ Sink the Bismarck SH3 Movie

03-05-08, 12:11 PM	#8
DavyJonesFootlocker The Old Man Join Date: Dec 2007 Location: Stink Drunk in Trinidad Posts: 1,572 Downloads: 138 Uploads: 0	No. I meant that yes, in those conditions it can be seen, but what about less favorable conditions. Remember a helicopter took that one. A plane flying at 300 mph or more may not pick it up. __________________ "Silence means death. Stand on your feet. Inner fear your worst enemy."- Sepultura. My Silent Hunter 5 mantra is this......"Torpedo missed, sir!" A P-400 is a P-40 with a Zero after it. A proud member of the Wikipedia Haters Club

03-05-08, 12:48 PM	#10
Ducimus Rear Admiral Join Date: May 2005 Posts: 12,987 Downloads: 67 Uploads: 2	The short of it its, in terms of undewater visual detection, you can control the RADIUS in which it is possible, just not the depth. So by virtue of lowing a varible (exact name illudes me at the moment, short on sleep, groggy, still on 1st cup of coffee), you can make this detectioin radius larger. By raising this number, you can make the detection radius smaller. Detection radius is important, because your giving the plane TIME to see you. For detection to occur, the AI must see X amount of your sub, for Y time. Since planes travel so fast, they can zip right though this radius before they can regester a sighting. So you can only make the detection radius so small. I think its around 3,000 meters is what i have it at. The stop gap, was adding "Thermal Layer Signal Attenuation=5.0" to the visual sensor in the sim.cfg. At least, its hopped that works in stopping deep detection, if your below a layer. These are the limitations imposed by the agme engine. When you make the game do something it wasnt orgianlly intended to do, its not going to work perfectly. But it works well enough, and the positive aspects to gameplay, far outweigh the occasional "WTF".

03-05-08, 01:50 PM	#11
MONOLITH Grey Wolf Join Date: Nov 2002 Posts: 997 Downloads: 0 Uploads: 0	You guys actually had a good discussion on this quite awhile ago, including some good pictures/diagrams of the radius issue. Wish I could find those right now... Question Ducimus... I assume the radius prevents you from being spotted, when you dive to a depth that puts the top of the radius underwater, yes? And can you say, in TM, about what that depth is, or do other factors complicate that being a simple answer? __________________

03-05-08, 02:03 PM	#12
Major Johnson Frogman Join Date: May 2007 Location: Jeresey Shore USA Posts: 288 Downloads: 25 Uploads: 0	I would say that in real life the weather plays a big part of this equation. On a clear day and calm seas, I wouldn't be surprised to hear that a sub is visible down to 100 ft. In bad weather, ie, rain, chances are there's not going to be planes flying anyway. Another point was made about how high the plane is flying. Another good point, but for the sake of this game, I would say every plane is flying at a height normal for looking for subs. No point in having high level bombers. Also the cruising speed of most sub hunting planes wasn't 300 mph, it was normally around 200 or below. The 300 mph range is normally getting close to the top speed of the craft flying level. I recall seeing photographs of Uboats that were under the surface, taken by our own WW2 anti sub patrols. Many of those were taken by slow/low flying blimps, but there were also personal craft used for ASW as well. So I have no problem with planes being able to see a sub at periscope depth during ideal conditions. On a side note, wasn't the Union ironclad "Monitor" found by a plane?? And I believe it was in 100 ft or so of water. __________________ MJ! ASUS Sabertooth 990FX R2.0 AMD FX8350 8 Core 4.0 Ghz CPU GeForce GTX 560 Ti PCIx Video Card 8 GB Corsair Vengence RAM Rosewill 850W Power Supply

03-06-08, 02:08 AM	#15
Binary101 Swabbie Join Date: Oct 2007 Posts: 11 Downloads: 125 Uploads: 0	Thanks for the replys, I dont know much about game modding, but as you guys said under the right conditions, ie clear weather, say from 11am to 3pm and at what places on the map the uboats will be detectable at periscope depth, is there something in game that could monitor all these? graphicly you can see the uboats already underwater why so why cant enemy planes and would this be good in game?