Tests on Destroyer Visual Ranges

[WernerSobe]

Ive seen complains about 1.3 ai visual range being unrealistic.

Ive ran some tests using clean 1.3 install. Ive set up a single mission where a destroyer (asashio, competent skill, mid43 layout) is passing by my surfaced sub and recorded the ranges when my crew has spotted him and when he has spotted me.

The results:

During the day at best weather i can spot them from 8700 yards. They spot me from about 7000 at an angle of 60.
Waves seem to have no impact on that. The ranges were the same at windspeed of 15.
When there is light fog they spot me first from a range of 5000 and open fire before my watch has reported them. Which is ok because 5000 is realy not much and if you use external camara from the destroyer view, you can see your own sub clearly.

At night during best weather i can spot them again from about 8700. They spot me from 3600. Same with windspeed of 15.
Light Fog makes me spot them from 5000 but they didnt spot me at all and the ship passed by at a range of 2600. I could even attack it surfaced and they didnt see it coming.

So in my opinion the visual ranges are OK and realistic. You just have to keep in mind that light fog during the day drops your own visibility a lot and you are risking being detected first. You can run surface attacks at night, just make sure you are more then 4500 yards away when there is no fog and about 3000 when there is light fog.

[-Pv-]

Excellant data. Thank you.

Have you run tests with various crew experience to see what impact that was? If you didn't try different crew, did you record the crew compartment efficiency percent for the bridge? Did you note the fatigue level (although because you were running a short custom mission it was probably zero.)

-Pv-

[tater]

That seems like it might demonstrate that the type13 radar is no longer detecting ships, too (mid 43 asashio has that radar). Cool!

tater

[WernerSobe]

Excellant data. Thank you.

Have you run tests with various crew experience to see what impact that was? If you didn't try different crew, did you record the crew compartment efficiency percent for the bridge? Did you note the fatigue level (although because you were running a short custom mission it was probably zero.)

-Pv-

crew effectiveness was 100% and it was a competent crew setting.

Its realy not hard to have 100% for the watch. I usualy have it from the beginning of a campaign without extra crew members. You have to drill them a lot to drop it below 100.

Their spotting was very realistic at current visibility conditions. They have spoted the ships about same time they became visible. So i havent expirienced them being blind or spoting ships that i couldnt see.

[Jaeger]

would be interesting to know, when they can detect the raised periscope.


werner, you wrote, that it is realistic. but in real live, you can see a ship like a destroyer in more than 8700 yards. the maximal distance of view is computed by this short formular: radical of height (in meters) of your position multiplied by 3.57 (result in km)

for example: the bridge of your submarine is about 3 meters over ground. radical of three is 1.73 multiplied by 3.57 makes 6.18 km maximal distance of view (while clear weather of course). i think you can see ships too late in sh4.

greetz, Jaeger

[NefariousKoel]

Yes...

Periscope spotting range is what has irked me so much thus far.

[SteamWake]

Yes...

Periscope spotting range is what has irked me so much thus far.

How so.... you can spot from to far ?

I had a suspicion this was true but I dont mind :p

[nattydread]

I dont mind the range the AI DDs can spot my surfaced sub during the day, I just cant stand how much they handicap player visibilty due to the persistent max visual range fog.

It means I cant seem to maintain good visual contact on ship when running an end-around...the fog severly deminishes my ability to guage AoB and spit out rough track for the DD.

[Rockin Robbins]

Incredible work Werner!

My experiments with "high periscope watch" lead me to believe that eye height is not factored in at all when calculating SH4 horizon distance. I can see no further from a fully raised periscope on a surfaced submarine than I can from the deck. There should be a dramatic difference. A ship hull down from the deck should be way above the horizon from high periscope watch. It isn't.

Capt Gene Fluckey credits high periscope watch with doubling his search area (that doesn't mean doubling horizon distance, Remember your analytical geometry!).

[tater]

I think for a "high periscope" watch to work the view distance would need to be increased from the default. The problem might be that the horizon distance in game is about equal to the RL distance from the shears so increasing the height wouldn't matter. What is the visible distance 4-5 miles?

http://members.spinn.net/~merrick/Stuff/range_table_sm.jpg

[Rockin Robbins]

Sorry, posted to wrong thread. See in WernerSobe's Realistic Sinking Physics thread in SH4 Mods board.

[Rockin Robbins]

I think for a "high periscope" watch to work the view distance would need to be increased from the default. The problem might be that the horizon distance in game is about equal to the RL distance from the shears so increasing the height wouldn't matter. What is the visible distance 4-5 miles?
Duh!!!!!! You're absolutely right. If the deck is 5' off the water the horizon is 5190 yards away. High periscope at 23' (or close to that) would have a horizon distance of 11,120 yards, much greater difference than I envisioned. But SH4 has a max visibility of what? Must be little more than half of that. Wish I could mod! That could be fun to play with if the parameters are available. But you sure answered the question.