Fog of war / river crossing bug detected

[Skibear]

I was going to put this in the other river crossing thread but I think it probably warrants a seperate thread.

In a current game against Manstein (patched to 1.10a) then he was strongly dug in around Alexandria and Washington so I send Lee with Jackson and Early's corps on a rampage sacking Baltimore and Wilmington and then headed back via Gettysburg to Harpers ferry to draw him out. This worked nicely and sucked out the Union hordes who smelt blood. However this allowed Longstreets corps of 5 Divs at manasas to see a window to strike Washington which was relatively undefended as Alexandria was empty. At the same time in the west I saw a window to attack north with 4 divisions to try to retake Memphis which had only 2 divisions defending.
So anyway success, Lee (just!!!) slipped his pursuers and avoided destruction and got back to Harpers ferry just as the attack went in on Washington. Longstreet stormed in to the lightly defended capital and took the city. Happy days CSA NM 178 Union 48. One step from total victory in a very enjoyable game that also saw Forrest and Van Dorm taking St Louis in 62 and still holding out...
However, quite rightly Manstein pointed out that he had fleets blocking the Potomac and also in the west he had fleets covering the river there too.
We reloaded the last turn and checked and it seems that fog of war prevented me seeing his fleets on that river and the potomac. This allowed me to enter offensives over both rivers. And it seems that with river crossings so long as you cant see any gunboats you proceed across the river quite happily oblivious to them!! Seems a bit of a bug there (much as I hate gunboats at the best of times! ) ) that may require looking into. Has this been raised before? Maybe a simple fix is gunboats are never in fog of war, but sure thats a hateful comprimise for many players. However if you can enter orders when you dont know there are gunboats present and then you are blocked thats a turn wasted, or potential disaster caught on the wrong side of the river when maybe you had other options.
For me this lends weight to the game mechanism being that boats only have a percentage chance of blocking a crossing. Maybe a high one on a sliding scale if the numbers are high enough. But it seems that if the union can rely on just a handful of ships to guarantee that Washington is defended from Alexandria then he will have a big big advantage in being able to leave much much less troops to defend washington than Lincoln had to devote historically. But maybe this is a big side issue. The principal reason for this thread is to highlight the issue that it appears that boats not detected by fog of war do nothing to prevent enemy movement.

[GShock]

Ski, attach the save for Pocus to see pls.

[Gray_Lensman]

deleted

[Manstein]

Hi Gray.

The game is the same, because Ski is the South and I´m the North. Seems that the problem is not the Alexandria-Port Tobacco link, because Ski says that Longstreet crossed from Alexandria to Washington, but he commences the movement form Manassas and Alexandria was North controlled at 100% and he didn´t see the north fleet at Potomac (the same at Tallahatsie river), and Ski thinks that the problem can to be the fog of war: his troops do not see the ships blocking the rives, so he give the order for cross and the order is resolved as if the fleets were not here.

(sorry for my english)

[Pocus]

This bug should not be, because this loophole should have been taken of. I must have missed something in the code in this case.

The host should send me current turn + backup1 (before crossing).

[arsan]

Hi!
Pocus,
I don't know if skibear sent to you the saves. But in case it is needed, here you have another set of saves with this porblem, sent to me by another Spanish player (Antonyo).

He reports you can check the "ilegal" river crossings because of the fog of war by looking at G. Smith command moving from Culpeper to Washington even when the Potomac crossing is blocked by USA ships.

On the atached current turn the illegal move is already completed. You must check the backup turn to see the movements by yourself.

Also there is another problematic movement made by 1st SC Bde and Norflok Guns from Culpeper to Port Tobacco. But this second case is probably related to the wrong link reported before and already fixed by Gray.
The important one is IMHO the Culpeper-Washington one.
Hope it helps
Regards!

[Jagger]

There is definitely a problem with ships and blockades which appears related to FOW.

Rivers, without troops adjacent, have a spotting capability of 1/0. Which means rivers have a 0 sea spotting ability against ships.

Shallow and shallow (may freeze) river terrain have a -2 detection modifier to units. So a gunboat with a hide value of 3 should be modified to 1. Thus the river spotting value of 0 is still too low to spot gunboats with a hide value of 1even with the modifier--unless troops are present to increase the sea spotting value.

If the gunboats are not spotted, then they will not appear to the opponent nor block river crossings. Which creates major problems when attempting to blockade rivers in areas without enemy troops present.

I tried modifying gunboat hide values to 1 and 0 which should produce modified values of -1 and -2. Still gunboats were not spotted on a river with a 0 spotting capability. Thus no blockade.

Something is definitely not working properly. This problem can have a significant negative impact if you think you have a river blockaded but then the enemy simply moves right over the river.

[Jagger]

There is definitely a problem with ships and blockades which appears related to FOW.

Rivers, without troops adjacent, have a spotting capability of 1/0. Which means rivers have a 0 sea spotting ability against ships.

Shallow and shallow (may freeze) river terrain have a -2 detection modifier on ships. So a gunboat with a hide value of 3 should be modified to 1. Thus the river spotting value of 0 is still too low to spot gunboats with a hide value of 1--even with the modifier--unless troops are present to increase the sea spotting value.

If the gunboats are not spotted, then they will not appear to the opponent nor block river crossings. Which creates major problems when attempting to blockade rivers in areas without enemy troops present.

I tried modifying gunboat hide values to 1 and 0 from the original 3 hide value which should produce modified values of -1 and -2. Still gunboats were not spotted on a river with a 0 spotting capability. Thus no blockade.

Something is definitely not working properly.

This problem can have a significant negative impact if you think you have a river blockaded but then the enemy simply moves right over the river, straight through the blockade and smashes your forces. When you thought you were perfectly safe as the enemy should not have been able to cross the river due to the blockade.

[Coregonas]

I believe than there are 2 problems here:

1.- This program "bug" -> doesnt works WAD

2.- WAD should not be 100% sure the enemy not to cross.

If a player knows there is a (even a minimum 1-5%) chance to cross, then it should be his fault to allow this.

The chance should be very small, to encourage USA player to pay for all those ships, and be usefule still, but not a ALL or NOTHING chance.

I believe really ATHENA GREATEST skill is UNCERTAINTY.

We players desire normally EXACT values, but this UNCERTAINTY adds to the game an extra 100% to try simulate reality.

[Pocus]

Hi!
Pocus,
I don't know if skibear sent to you the saves. But in case it is needed, here you have another set of saves with this porblem, sent to me by another Spanish player (Antonyo).

He reports you can check the "ilegal" river crossings because of the fog of war by looking at G. Smith command moving from Culpeper to Washington even when the Potomac crossing is blocked by USA ships.

On the atached current turn the illegal move is already completed. You must check the backup turn to see the movements by yourself.

Also there is another problematic movement made by 1st SC Bde and Norflok Guns from Culpeper to Port Tobacco. But this second case is probably related to the wrong link reported before and already fixed by Gray.
The important one is IMHO the Culpeper-Washington one.
Hope it helps
Regards!

Bug fixed, for the next patch. The interdiction was properly calculated when hosting, but for some reasons, the test to check for it was misplaced.