i want to have them at 0kn and then at a defined time (trigger) i want them to accelerate to max. speed.

worth to try it out, thank you. i didn't know that one can assign a speed to a waypoint....but i will see......

Guys, use your brain. :damn:

Set the uboat engine power to 10% of it's original power and go for a ride.

I already did it. And as I said before, the max speed doesn't change, just the time to get there.

:up:

BUT THAT'S SUPPOSED TO HAPPEN!!!

I still don't understand what you want to fix!

You can do some neat stuff with mission Editor.
A usually use it to do Stunt flying for aircraft!
I'll script 5 aircraft flying in a wedge and have them increase speed and
start a split as they climb!

It's awesome to watch!
Sometimes I add Smoke in different colors just
for the thrill!
FPS really takes a hit but it's so Danged COOL!!

Here's an early example of Stunt Flying.
http://s108.photobucket.com/albums/n...ent=Fly_By.flv

the acceleration ability "linked" to the moment of inertia and not to the drag.

in other words,

if you get lower the power and increase the drag, you get a slower acceleration ability due to low power and high drag effect.

An other way to reach this, is mantaining the stock power, and increase the inertia momentum (that I don't know where is and if exists in sh3!). In this way you will have the same effect on take down the acceleration ability, but without a so big slow down effect during the turning.

it is obvious to use an uboat for testing, but I'm not sure wheather freighters and uboats use the same implementation of aqua-dynamic model. sh3 uses so many inaccurate simplifications.....being pedantic and perfectionist, I prefer to do my testing with merchants to avoid unknown effects that falsify my results.

thanks, privateer. but my mission editor is hard to use (buggy?). if i move the mouse to a certain point (e.g. x=20, y=20) in order to place a ship at that position, the editor places the ship far away, at x=60, y=60. and it's very hard to mark units in order to change their properties.

Servus h.sie!

Do you use the hi-res-fix (d3d9.dll)?? If yes, you had to rename this file temporarely and than start the mission-editor. Because hi-res-fix and mission editor don't like each ohter. :oops:

Hope this helps.

Sag wrote: "An other way to reach this, is mantaining the stock power, and increase the inertia momentum (that I don't know where is and if exists in sh3!). In this way you will have the same effect on take down the acceleration ability, but without a so big slow down effect during the turning."

yep. the moment of inertia is proportional to the mass (if the mass is concentrated in one single point). one needs to enlarge the mass in order to get a higher moment of inertia and a lower acceleration. F(orce) = m(ass) * a(cceleration), so that

a = F/m.

One can edit the ships mass using S3D, but I'm afraid of unexpected side-effects....if I remember right, the mass is defined a) in the cfg-file of the ships and b) in the sim-file. I guess that the mass in the cfg-file is used for the recognition manual only and has no physicalic effect, while the mass in the .sim-file is used for the physicalic behaviour of the ship model. but I'm not sure, because I'm not a modder. I only want to have an halfway "realistic" game.

Yes, I use it. Thank you very much for your help. (This is a really cool forum.) One gets so much help. ...... wow. so many competent people here. what about programming an own subsim-simulator instead of debugging an buggy commercial game? (but without me, I program 8 hrs/day.)

hi mikhayl:

I agree. I've stopped programming my tool which automatically sets values in the sim-files, because there must be research BEFORE programming. i have no experience with ships, except my rudder boat for fishing purposes, but according to my "feeling", i would estimate, that a speed reduction from 15 to 10-12knots would be okay when zigzagging.

a friend of mine is commander of a (real) frigate. i meet him next week and i'll ask him about that problem. in the next time, i will play around with the params (mass, drag, eng_power etc.) in the unit_Ship section of the sim-files for diffferent ship types. perhaps we could exchange experiences. but i don't know if it's polite to use this thread for that?

h.sie

Hi to all, I tried to modify the mass of U-boat. I found very strange behaviours.

If I increase 10fold the U-boat surface desplacement, the Uboat floats on sea surface!
If I decrease 10fold the U-boat surface desplacement, the U-boat sink as a rock!
But, if I increase the U-boat mass (the vaule before surface/immerged nodes), the boat goes down as a rock!

And there isn't any value apparently linked to inertia momentum. SH3 plays with engine power and xyz drug coefficients, but probably the mass is linked only to floating properties..:hmm:

it's weird. Probably U-boats are not usefull for this kind of tests..

Wow, "GWX 3: Secret Weapons of the Luftwaffe" is coming :up:

1. The rudder drag is related to how fast the ship will turn, and have almost nothing to do with how much speed will the vessel lose while turning.

2. A ship like a battleship, with a lot more power-per-ton coeficient than a merchant, with 3 propellers instead of one as a merchant, and with a lot better hull for speed, while turning would likely lose half of it's speed. I have those numbers. Now, are you telling me that a big tanker, doing 15kts, (which is a great speed for a tanker, but would be impossible while turning), and dropping to 5kts while zig-zaguing is absurdly irrealistic? You said yourself that you don't know what would be the accurate speed for a ship like that in conditions like that, so why are you questioning so hard about realism?

3. The rudder drag for merchants is set at 0,02. If you decreases that, the ship turning radius will become VERY large, there goes a lot of irrealism. I tested a lot this parameter, 0,02 is the smallest value you can imput on merchants. The stock value/gwx value would be 0,03.

4. You guys are talking beautiful maths, but sh3 don't allow us to party around with zillion values. If you open ship.sim in s3d, you'll see about 20 values, and only 2 of them are related to how much speed ships will lose while turning.

a) the engine power: sure, increasing the engine power to a kazillion would make the ships mantain the same speed while turning, but also would make them behave like a jet-fighter. The engine power as it is right now is the closest to realistic accelerating we can have.

b) the drag left-right: the ammount of drag between the hull and the water when moving left-right. In other words, the ammount of friction between the hull and the large ammount of water that is deslocated while turning, cos the ship is "pushing" tons and tons of water out of the way when turning. Remember, a ship does not turn like a car, front first cutting the water and the rear follows. Nope. The front does nothing, the rear pushes left or right, moving zillion tons of water out of the way, changing the heading. The value in my mod is 0,75. If you decrease that, yes, the ships will start to turn a little bit faster, but this is also the value that controls the "bobbing", so if decreased the ships would be back as gwx, behaving like rubber ducks in a bathub. Pointless.

Now, what can be done to improve the ship's maneuverability while turning, that would not be realism killer?

Increase the engine power by 100%. Yes, doubling the value.

This mod took the engine power and reduced to 10%. Now if you double it, you'll have about 20%. And 20% will not ruin too much their acceleration and breaking abilities, and will improve their speed while turning.

Why?

Simple, they will have more engine power, and that engine power will be able to sustain more speed while turning, the relation between power/drag will be bigger.

While hasn't it been done already?

I'm waiting h.sie finish his tool so I don't have to manually change 200 ships.

:up:

If you increase 10 tons in the displacement, you also have to increase 10 tons in the mass. Otherwise, the uboat becomes umbalanced and sinks, or floats.

Additional info:

The merchants have a particular maneuverability. Destroyers have another. Escorts also are different from destroyers and merchants. Battleships too.

So you cannot just find a right value for one ship and apply to all the others.

And no, I don't mind this kind of discussion in my thread. It's actually healthy. Like I said before, any kind of feedback can be constructive for the next update.

And like I said so many times, none of my mods are finished. They are constantly upgrading, based on feedback and discussions like this.

:up:

"If you increase 10 tons in the displacement, you also have to increase 10 tons in the mass. Otherwise, the uboat becomes umbalanced and sinks, or floats."


thanks, I'll test changing both :up:

I ve made a test scenario, in which a troup transporter suddenly had to accelerate from 1kn to its max. speed of 17kn. wind: 15m/s comes from ahead.

with eng_power = 10000 (original value) it accelerated to 17kn in a too short time.

with eng_power = 1000 (10% value from PT) it accelerated slowly, but it did reach 17kn a long time later - as desired!!!

i cannot believe that. in my opinion this is impossible in real life, because the machines have to overpower the speed-proportional resistance of the water. I'm sure, that in RL an engine with only 10% power can never reach the same max. speed as a 100% power engine (this is only possible in an ideal system without resistance). if weak engines lead to the same speed, there would be no need for strong and expensive machines.

but in sh3 it seems to work, perhaps because of a very simple physical model implementation.

unbelievable.. I'm agree with you about RL! but that is in SH3! thank you for your experiment that give us the confirmation that drag in SH3 behaves in a different way by RL!

So... just a thought :hmm: .. is drag in SH3 more like an inertia momentum :huh:??

..and probably the SH3 water has not friction!! (I can stop the boat by stopping the engines probably because of drag value assigned to my boat, and not by the effect of a water value :hmm: ...?)

I told you guys about a zillion times, but you had to go test yourselves. Now you're beggining to understand the problems I'm facing.

But you're not understanding. You cannot change the rudder drag, cos otherwise the ship won't turn. If a ship turning radius is 1 mile with 0,02, it will be 2 miles with 0,01.

The data is somewhere on this thread...