Recoded Weather fix - envsim.act

[Hooston]

The distance to the horizon is explained well by wikipedia https://en.wikipedia.org/wiki/Horizon. In practice refraction will increase this slightly as explained in the article and obviously haze will decrease it. To summarise:

d=sqrt(2hR) where h is the observer height and R is the radius of the Earth, 6371000m.

Horizon distance for your uboat man with an eye height of 5m is therefore 7982m. Is this driving the design of the original game? However, to get the visibility distance to an object you add the observer's horizon to the target horizon, so in ideal conditions:

• you should see the top of a 30m mast at 7982+19551=27533m
• If you are looking for a 100m funnel smoke plume then you get around 44km.
• Similarly, a spotter 30m up in a battleship will see a 40m mast at 42km.

Best conditions daylight reporting in my old "16km" SH3 is around 14km. I'm not sure when objects spawn into the game - is it 32km?. The daylight distances are much too short. This is frustrating as it makes following a convoy in most weather conditions much harder than it should be.

At night you should be getting a blend from approaching daylight to roughly zero depending on conditions and crew equipment/training. For example:

• The Italian cruisers at Matapan (https://en.wikipedia.org/wiki/Battle_of_Cape_Matapan) failed to spot battleships at 3500m.
• At the battle of Savo island (https://en.wikipedia.org/wiki/Battle_of_Savo_Island) US destroyers were detected visually by the Japanese on different occasions at 16km, 9km and 12.5km; but USS Blue failed to spot cruisers about 2000m away!
• Early war uboats were regularly getting to a few hundred metres from merchants without being detected.

So I think you have the typical modder's problem of trying to fix something fundamentally broken. I suggest:

• Maximum visibility in full moon no better than daylight (assuming you cannot fix the daylight model!), that's around 14km for me and seems OK.
• Make the best case uboat AI's ability compatible with the player's with a monitor and graphics setup to standard gamma in a room with artificial light.
• The merchants should be VERY bad and the warships almost as bad unless at action stations (or centimetric radar equipped)
• I find the game much more exciting when I can only see about 1km. Is this a good "no moon but clear" number for uboats spotting merchants?
• The absolute figures are less important than the balance between uboat and ship spotting. Maybe scale the uboat vs ship visibility in line with relative size including an allowance for the size of the wake?