[REL] Rockets mod

Originally Posted by gap

What rocket is the 217 m/s figure relative to ?

The 5" FFAR. From Wikipedia : Performance was limited because of the increased weight, limiting speed to 780 km/h (= 217 m/s).

Originally Posted by gap

I don't know if velocity inherited from the launching aircraft is simulatred in game for gun shells. An easy way to test it would be giving the rocket launcher a ridiculously low speed, and see if the rocket falls down almost vertically rather than following a parabolic trajectory.

I think it's not simulate, but that's just my opinion. Tests are needed to check.

Originally Posted by gap

On an unrelated note, long ago I had an idea for making rockets to disappear from their racks after launch, but never had time to test it:

I though about that too. Have to try !

Originally Posted by gap

- make it destroyable, and create a new zone for it with a very low AP value (so that it can take damage from an explosive charge with low penetration properties) and a very high HP value (so that even if damaged by normal ordnance, it wont be easily detsroyed as long as its parent projector is not destroyed)

You mean AL, not AP ? Armor level ?

Originally Posted by gap

- create a new muzzle flash effect for the virtual rocket gun, and make it to spawn an explosive charge (similar to TDW's fire effects)

What is TDW ?

[gap]

Originally Posted by Kendras

The 5" FFAR. From Wikipedia : Performance was limited because of the increased weight, limiting speed to 780 km/h (= 217 m/s).

Originally Posted by Kendras

I think it's not simulate, but that's just my opinion. Tests are needed to check.

Maybe. If it wasn't, increasing rockets nominal speed by taking aircraft speed into account would be realistical

Originally Posted by Kendras

I though about that too. Have to try !

Originally Posted by Kendras

You mean AL, not AP ? Armor level ?

I think in the editors is called AP for "Armor Piercing", but yes, we are talking about the same thing

Originally Posted by Kendras

What is TDW ?

TheDarkWraith aka RacerBoy

P.S: have you seen post #43 in this thread?

Originally Posted by gap

I think in the editors is called AP for "Armor Piercing", but yes, we are talking about the same thing.

No. You have different shells types : AP (armor piercing) and HE (highly explosive). In Zones.cfg, you have Armor Level and HP (hitpoints).

Originally Posted by gap

P.S: have you seen post #43 in this thread?

Yes. I was on the point to answer you. Well very nice models, that's sad that it's not the rockets that I have worked on ... So we have to think about modelling them, on the base of yours. So here is my idea : I release a first version of my work (kind of beta test) with no highly modelled rockets, and we work for a second versions with improvments.

I would like to have something simple : 3 types of rockets :
- first as anti-submarine warfare (with no explosive head, just piercing) : 3.5" FFAR
- second which is the same with explosive but low speed : 5" FFAR
- third with explosive and better speed : 5" HVAR.

About R4M rockets on the Me262, it's just for fun, these rockets were against bombers airplanes, and I doubt that they could be used against shipping.

Originally Posted by gap

Rocket's accuracy was an issue even in real WWII warfare.

Sure, but in-game, the rockets just missed EVERYTIME, they were ALWAYS shot in front of the ships, whatever the distance between airplane and target, kind of wrong computering.

Originally Posted by gap

If you send me the library files where you have stored the rocket launchers and projectiles, I will update them with the models I have ready so far

Here are the .dat files : could you tell me if my models have the proper size please ? I think that the 5" rack/rocket is a bit too big and/or the 3" rack/model too small ... What do you think ?

http://www.mediafire.com/file/u82897...ts_Library.zip

[gap]

Originally Posted by Kendras

No. You have different shells types : AP (armor piercing) and HE (highly explosive). In Zones.cfg, you have Armor Level and HP (hitpoints).

In the AmmoDamageInfo the same value is called AP, but we can call it whatever as long as we understand each other

Originally Posted by Kendras

Yes. I was on the point to answer you. Well very nice models, that's sad that it's not the rockets that I have worked on ... So we have to think about modelling them, on the base of yours. So here is my idea : I release a first version of my work (kind of beta test) with no highly modelled rockets, and we work for a second versions with improvments.

Rockets are very simple objects and on the web there is plenty of information and drawings of them. Modelling them shouldn't pose any problem, but may I ask why you decided not to include British rockets in game? The British were the main and the closest German enemies (whereas American fighters were mostly deployed in the Pacific and in the Mediterranean, their usage in the Atlantic being limited mostly to to escort-carrier-based airwings), and their usage of airborne rockets in ASW role is well documented. Directly or indirectly, they caused the loss of severla U-boats, and they might have played a role in the early dismissal of Doenitz U-Flaks. In my opinion your mod shoudn't miss them

Originally Posted by Kendras

Sure, but in-game, the rockets just missed EVERYTIME, they were ALWAYS shot in front of the ships, whatever the distance between airplane and target, kind of wrong computering.

I see. Just in case, have you tried playing with the max range/angle and the elevation speed of their gun? Those parameters might play a role.

Originally Posted by Kendras

Here are the .dat files : could you tell me if my models have the proper size please ? I think that the 5" rack/rocket is a bit too big and/or the 3" rack/model too small ... What do you think ?

You can check yourself: 1 unit legth in Wings3D is equal to 10 m in the real world. WWII rocket sizes are well documented on the web.

The rockets should look more or less like this:


3.5" FFAR. Dimentions:8.255 cm motor diameter; 8.89 cm warhead diameter; 139.7 cm total lenght = 114.3 cm motor length + 25.4 cm warhead length. These dimensions are not compatible with the drawing on the right, which is too short, but they are with the picture on the left.

The picture below shows the 2.3368 m-long channel-slide launchers. According to wikipedia they were causing eccessive drag and they were replaced with zero-lenght launchers in May '45.




5" FFAR, basically a 3.5" motor with a 5" HE warhead in place of the solid steel warhead of its predecessor (8.255 cm motor diameter; 12.7 warhead diameter; 1.651 m total length)

I am not too sure about the warhead in the drawing above though. After having considered several pictures, I think the 5" rocket came in two versions. In one of them, the warhead is fitted with a pointed nose fuze:



At first glance the second version looks almost identical, except for the fuze, which looks more blunted:



I wonder if .they really are different fuzes, or rather the fuze could be covered with a pointed nose cap absent from some pictures. In any case the aforementioned drawing seems a poor representation of the "smooth-nose" rocket.

Last, a close-up picture showing a detail of the fin assembly:



Also note the "zero-length" launchers, visible in the three pictures above.



The 5" HVAR. Dimensions: 1.7272 m total lenght; 12.7 cm diameter; 39,6875 cm wingspan.

Again, pictures available on the web show the rocket either in the pointed or smooth-fuzed wahead configurations:


pointed nose


smooth nose

a detail of the exhaust (replica):


Drawings of the zero-length suspension stubs:

Originally Posted by gap

In the AmmoDamageInfo the same value is called AP, but we can call it whatever as long as we understand each other

Ah yes, I see what you mean.

Originally Posted by gap

may I ask why you decided not to include British rockets in game?

Because I wanted a simple mod with a few rocket types, and I had only bad models. But now, you're here to bring new stuff, and that's good !

Originally Posted by gap

The British were the main and the closest German enemies (whereas American fighters were mostly deployed in the Pacific and in the Mediterranean, their usage in the Atlantic being limited mostly to to escort-carrier-based airwings), and their usage of airborne rockets in ASW role is well documented. Directly or indirectly, they caused the loss of severla U-boats, and they might have played a role in the early dismissal of Doenitz U-Flaks. In my opinion your mod shoudn't miss them

Well, you convinced me !

Originally Posted by gap

I see. Just in case, have you tried playing with the max range/angle and the elevation speed of their gun? Those parameters might play a role.

Yes exactly, and it changed nothing. Except when I tried an angle of 90°, the rockets were near zero speed....

Originally Posted by gap

You can check yourself: 1 unit legth in Wings3D is equal to 10 m in the real world. WWII rocket sizes are well documented on the web.

Well, I have to learn how to measure objects in Wings3D ...

Originally Posted by gap

3.5" FFAR. Dimentions:8.255 cm motor diameter; 8.89 cm warhead diameter; 139.7 cm total lenght = 114.3 cm motor length + 25.4 cm warhead length.

2.3368 m-long channel-slide launchers.

5" FFAR, basically a 3.5" motor with a 5" HE warhead in place of the solid steel warhead of its predecessor (8.255 cm motor diameter; 12.7 warhead diameter; 1.651 m total length)

The 5" HVAR. Dimensions: 1.7272 m total lenght; 12.7 cm diameter; 39,6875 cm wingspan.

Well, it's very precise !

[Anvar1061]

Originally Posted by Kendras

Well, it's very precise !

The devil is in the details!

[gap]

Originally Posted by Kendras

Because I wanted a simple mod with a few rocket types, and I had only bad models. But now, you're here to bring new stuff, and that's good !

...and you inspired me with a series of amazing mods

Originally Posted by Kendras

Yes exactly, and it changed nothing. Except when I tried an angle of 90°, the rockets were near zero speed....

Okay. On a side note, how did you set the parameters of the 3.5" FFAR launcher? In theory the shooting aircraft should aim for the water line, slightly in front of the target:

Originally Posted by https://en.wikipedia.org/wiki/3.5-Inch_Forward_Firing_Aircraft_Rocket

The warhead contained no explosive. The rocket's nose was a solid steel mass, weighing 20 pounds (9.1 kg), that punctured the pressure hull of a target submarine through the kinetic energy and momentum from its high velocity and mass. The nose of the 3.5" FFAR was given a relatively blunt conical shape that had been shown experimentally to give a maximum pitch-up of the nose as the rocket entered the water. This caused the rocket to shoot forward at a shallow depth deadly to submarines that were surfaced or traveling at snorkel or periscope depth. The rockets were launched in a shallow dive, since entry into the water at too steep an angle would defeat their ability to shoot forward at the required shallow depth. The rocket remained lethal even after passing through up to 130 feet of water, giving the pilot a target several times the actual size of the submarine. The sweet spot for targeting was considered to be 60 feet in front of the near side of the submarine. Typical firing range was about 1500 yards.

I don't know if something like that can be simulated in game though

Originally Posted by Kendras

Well, I have to learn how to measure objects in Wings3D ...

Everything about WIngs3D is very simple and intutive: select an edge, and you can read its length on the left of the top bar; select two vertices, and their distance (absolute and on the three axis) is shown in the same spot

Originally Posted by gap

I had an idea for making rockets to disappear from their racks after launch, but never had time to test it:

- attach a rocket model to each launcher as a separate mesh, near the (virtual) gun muzzle;
- make it destroyable, and create a new zone for it with a very low AP value (so that it can take damage from an explosive charge with low penetration properties) and a very high HP value (so that even if damaged by normal ordnance, it wont be easily detsroyed as long as its parent projector is not destroyed);
- create a new muzzle flash effect for the virtual rocket gun, and make it to spawn an explosive charge (similar to TDW's fire effects)
- set this explosion with a low AP value and a small blast radius (so that no other object but the rockets under aircraft wings will take damage from it), and an HP value high enough that the rocket in the rail gets detsroyed at once when a rocket is fired.

Testing now this "explosive" solution !

Originally Posted by gap

Everything about WIngs3D is very simple and intutive: select an edge, and you can read its length on the left of the top bar; select two vertices, and their distance (absolute and on the three axis) is shown in the same spot

Great !

I've just managed to put an explosive input on the rocket launch event !



So it should be easy now. Just have to tweak some parameters values.

[gap]

Originally Posted by Kendras

I've just managed to put an explosive input on the rocket launch event !



So it should be easy now. Just have to tweak some parameters values.

Amazing!

Note that the approach I suggested, if it works, might require each rail/launcher to be a separate gun. The reason is that the virtual muzzle that the explosive flash effect is spawned from, needs to be really close to the "unarmed" rocket model (the one attached to the rail), for it to be destroyed by the explosion.
When a multiple-muzzle gun is elevated/traned, its muzzles move away from gun's pivot point, so it it would be impossible making sure that the muzzles are always close to their respective rocket, unless we make rockets to unrealistically turn together with the virtual barrels. On the contrary, if we have separate launchers for each rocket, the one muzzle and the one roket can be placed on the same coordinates as the pivot point of the virtual gun, and the muzzle will alway "fire" its explosive charge at the center of the corresponding rocket, no matter whan gun's elevation/training is.

Some other advantage of having a separate gun for each rocket, is that we could place any number of rails under aircraft wings (2, 4, 5, etc for each wing) , we could have any combination of rocket rails (say for example 2 AP + 2 HE for each wing) and by moving the equipment nodes appropriately we could make each rail to follow more closely wing's profile.
The one downside that I can think of, is the time required to create multiple rocket hardpoints on aircraft models, and for setting their equipment files appropriately

Originally Posted by gap

Amazing!

Note that the approach I suggested, if it works, might require each rail/launcher to be a separate gun. The reason is that the virtual muzzle that the explosive flash effect is spawned from, needs to be really close to the "unarmed" rocket model (the one attached to the rail), for it to be destroyed by the explosion.
When a multiple-muzzle gun is elevated/traned, its muzzles move away from gun's pivot point, so it it would be impossible making sure that the muzzles are always close to their respective rocket, unless we make rockets to unrealistically turn together with the virtual barrels. On the contrary, if we have separate launchers for each rocket, the one muzzle and the one roket can be placed on the same coordinates as the pivot point of the virtual gun, and the muzzle will alway "fire" its explosive charge at the center of the corresponding rocket, no matter whan gun's elevation/training is.

Some other advantage of having a separate gun for each rocket, is that we could place any number of rails under aircraft wings (2, 4, 5, etc for each wing) , we could have any combination of rocket rails (say for example 2 AP + 2 HE for each wing) and by moving the equipment nodes appropriately we could make each rail to follow more closely wing's profile.
The one downside that I can think of, is the time required to create multiple rocket hardpoints on aircraft models, and for setting their equipment files appropriately

I perfectly understand and I agree with you.

[gap]

Originally Posted by Kendras

I perfectly understand and I agree with you.

Another possible advantage of the one rail/one gun approach is this:

Originally Posted by https://en.wikipedia.org/wiki/RP-3

A typical RP-3 installation was 4 projectiles on launching rails under each wing. A selector switch was fitted to allow the pilot to fire them singly (later omitted), in pairs, or as a full salvo. Towards the end of the war some RAF Second Tactical Air Force Hawker Typhoons had their installation adapted to carry an additional four rockets doubled up under the eight already fitted.

If a group of four rails is set as a single gun, they will always fire their rockets as a salvo. On the contraty, if each rail is a separated gun, depending on circumstances chances are that the AI pilot will fire his rocket loadout in two or more attack runs. There are things we could do for making this evenience more likely (like having two copies of each laucher/rocket to be fitted on the same plane, each with slightly different gun settings), though it actually happening is largely out of our control

Originally Posted by gap

When a multiple-muzzle gun is elevated/traned, its muzzles move away from gun's pivot point, so it it would be impossible making sure that the muzzles are always close to their respective rocket, unless we make rockets to unrealistically turn together with the virtual barrels.

Well, to be sure, I've tested by putting a flak fire effect at the place of the 4 muzzles rockets gun. Each muzzle effect is always centered on its own rocket.

Originally Posted by gap

If a group of four rails is set as a single gun, they will always fire their rockets as a salvo.

Not at all. You can separate each launch by the time you want. You just have to set whatever value you want for the recoil time (2 seconds for example). You can also simulate several separated salvos by setting a reload time (3 seconds for example), and you choose clip size=2 : that means that 2 rockets will be launched (separated by the recoil time) and 3 seconds will pass before another salvo of 2 rockets is fired.

Originally Posted by gap

On the contraty, if each rail is a separated gun, depending on circumstances chances are that the AI pilot will fire his rocket loadout in two or more attack runs.

No. In this case, all guns will fire at the same time.

About my tests. I don't manage to make the rockets destroyed when fired. The airplane (wings + engine) is destroyed (even with a min/max radius=0.000001 for the ammo damage). It seems that a very small explosion is impossible. I have tested further with max radius=0 : the wings are no more destroyed but the rockets still don't disappear. And when the airplane falls in the water, only the rockets on the left wing disappear because of the depth.