Scripted Aircraft in Silent Hunter 3 (SH3)

[Stiebler]

@Areo16:

The specific intercept that I use is in the code beginning at SH3Collisions.act+02e70. Register ebx points to the active unit.

This is particularly useful, in that:
a) only scripted units (including the player's unit) pass through this code. Randomly-generated units and land units have their own code. This saves a lot of computation.
b) The SH3Collisions.act code is mostly activated only when other units are sufficiently close to the U-boat that a collision (eg with a bomb or shell) might occur.

Thus scripted aircraft can only make my new code active when they are close to the U-boat, but before the U-boat is seen, and before a radar-warning given. Then, in poor visibility, the hit-points at float[ebx+00B8] are set to zero and [ebx+00D0] is also set to zero, which kills further movement of the aircraft.

But note how useful this is: if there are many scripted aircraft flying nearby, only those sufficiently close to the U-boat will be eliminated. The others will continue to fly their scripted routes even in bad weather, so they remain still a threat to the U-boat when visibility becomes better.

I have also revised my plan stated above to provide multiple scripts at 7-day intervals for periods of months in area north-west of Spain. As just stated, most of the scripted aircraft will survive poor visibility anyway, because the U-boat is not near. Moreover - I forgot earlier - most U-boat patrols will be of at least six weeks' duration. Therefore it is only necessary to provide scripts, not for every seven days, but for every six weeks - and at 2-3 month intervals when the air cover was present, but weaker, in the same area.

Stiebler.

[Hitman]

Here's an alternative for you: Make an invisible unarmed ship that is linked to an airbase (Aircraft carrier) that spaws the period appropiate aircraft. Then you have it patrol the Bay of Biscay or whatever area you want.

[Niume]

Hitmans sound smart But would it work? I am really intrested in this project because I rarely see aircraft

[areo16]

Originally Posted by Stiebler

@Areo16:

The specific intercept that I use is in the code beginning at SH3Collisions.act+02e70. Register ebx points to the active unit.

This is particularly useful, in that:
a) only scripted units (including the player's unit) pass through this code. Randomly-generated units and land units have their own code. This saves a lot of computation.
b) The SH3Collisions.act code is mostly activated only when other units are sufficiently close to the U-boat that a collision (eg with a bomb or shell) might occur.

Thus scripted aircraft can only make my new code active when they are close to the U-boat, but before the U-boat is seen, and before a radar-warning given. Then, in poor visibility, the hit-points at float[ebx+00B8] are set to zero and [ebx+00D0] is also set to zero, which kills further movement of the aircraft.

But note how useful this is: if there are many scripted aircraft flying nearby, only those sufficiently close to the U-boat will be eliminated. The others will continue to fly their scripted routes even in bad weather, so they remain still a threat to the U-boat when visibility becomes better.

I have also revised my plan stated above to provide multiple scripts at 7-day intervals for periods of months in area north-west of Spain. As just stated, most of the scripted aircraft will survive poor visibility anyway, because the U-boat is not near. Moreover - I forgot earlier - most U-boat patrols will be of at least six weeks' duration. Therefore it is only necessary to provide scripts, not for every seven days, but for every six weeks - and at 2-3 month intervals when the air cover was present, but weaker, in the same area.

Stiebler.

Thank you for this offset. This will help for many things.

[Stiebler]

@Hitman:

Here's an alternative for you: Make an invisible unarmed ship that is linked to an airbase (Aircraft carrier) that spaws the period appropiate aircraft. Then you have it patrol the Bay of Biscay or whatever area you want.

Hi Hitman, nice to see you're still around and active.

If your intention is: place an airbase on the aircraft-carrier, then NYGM has already a very similar solution for the Bay of Biscay. Specifically, it has an air-base placed 800m in the air above the western Bay of Biscay (completely invisible!) stocked with bombers of deliberately short (500km) range. This creates frequent air attacks on a U-boat trying to get in or out of the Atlantic. It is very effective, and forces all U-boats to hug the north coast of Spain to get to/from the Atlantic. There are constant air attacks.

The big problem is that it is impossible to move through the middle of the Bay of Biscay without very, very frequent air attacks. If you are returning from a patrol off Iceland, you have to return to base in a wide loop, finally coming up the west coast of Spain from the south in order to crawl along the north coast back to base.

Likewise, schnorchel patrols close to Britain in 1944-5 are hindered by constant attacks by aircraft spawned from land bases. The central problem is that the closer you are to an air-base, the more frequently aircraft from it attack (probably an inverse square-rule by the devs).

@Areo16:
Acknowledged with thanks.

Stiebler.

[Hitman]

Like you say, the problem with the fixed airbase is that you can't transit through the centre of the Biscay Bay without too frequent air attacks because the closer to it, the more air attacks. The solution of the moving airbase solves that by randomizing the location of the base itself, which moves over a zone.

[Anvar1061]

Will work this new SH3Collisions.act with my campaign_RND.mis, campaign_LND.mis & campaign_SCR.mis files?

[Stiebler]

@Hitman:

Like you say, the problem with the fixed airbase is that you can't transit through the centre of the Biscay Bay without too frequent air attacks because the closer to it, the more air attacks. The solution of the moving airbase solves that by randomizing the location of the base itself, which moves over a zone.

Yes, that is an interesting idea. The airborne air-base could probably be made to move in a scripted circle with random path at 800m above the Bay of Biscay. Also use aircraft with very short radius.

At the moment, I'm trying to raise the alertness level of the scripted aircraft that I mentioned previously.

@Anvar1061:

Will work this new SH3Collisions.act with my campaign_RND.mis, campaign_LND.mis & campaign_SCR.mis files?

Yes. Should work with any campaign files.

Stiebler.

[Stiebler]

I've now tested fully Hitman's idea of using a moving land-base for aircraft around the Bay of Biscay, using a moving special airbase floating at around 1200m in the air, and fitted with aircraft of limited range. The movement of the airbases can be seen clearly, if they are allowed to transmit their position every six hours.

This idea works very well, with a selection of two special aircraft. The aircraft require ranges of 300km, chosen by experiment, and the speed of the moving airbases is set at 50km/hr. The aircraft will not attack in medium or thick fog.

However, I have persevered with my original idea of using scripted bombers, as an addition to the moving airbases. The modified file SH3Collisions.act, mentioned earlier, prevents the scripted aircraft from appearing during fog.

Two observations are of interest:
1. When the stealth-meter turns red, it does not mean that the aircraft has detected you. You are detected when the time-compression drops to 8.
2. All the aircraft (scripted or spawned from a land-base) seem to be blind to the U-boat if it is not directly in their line of vision ahead as they fly close. As mentioned previously, the spawned aircraft are given a direct line of flight to the U-boat by the code before they are visible from the U-boat. This makes them deadly. The scripted aircraft can fly in a straight line past your U-boat without seeing it, even if it is close, unless the U-boat is by chance almost directly ahead of the flight of the aircraft.

I'm still trying to find out how to switch on the 'U-boat sighted' flag for scripted aircraft. But in the meantime the combination of moving airbase and scripted aircraft in the Bay of Biscay seems to give just the right level of air attack in late 1943.

Stiebler.