[TEC] The ships' behaviour at sea

[Fahnenbohn]

Originally Posted by TorpX

I was modding the ships' physics in SH4 a little while ago. This may or may not apply to SH3:

The LR (left-right) drag only affect turning. The UD (up-down) drag is for pitching.

I generally increased mass of merchant ships, assuming them to be heavily loaded.

Ship stability:

If you want to increase the extent of roll increase the gc height, if you want to decrease the roll, decrease the gc height. However, if you like the extent of roll, but want to make it slower, increase the draft slightly (the surface draft). Sometimes a very small change here will improve the stability a lot.

I had started out trying to manipulate the submerged draft of the surface ships, but ended up setting all of them to zero. The reason is that I found, if the submerged draft is not deep enough, the ships do not sink by flooding. That is, when torpedoed, they would settle down some, then sit there, impervious to flooding. Not good.

I had to do the ships stability mostly by trial and error, not having a mathematical guideline for this. It was tedious, to say the least.

Thank you very much for this interesting reply, TorpX !
Indeed, you are saving me a little time.
I have two questions :
- What is exactly the surface draft ? I can't translate it into French.
- What does happen if you increase the mass of a ship ?

[TorpX]

Originally Posted by Fahnenbohn

I have two questions :
- What is exactly the surface draft ? I can't translate it into French.

Surface draft is surface draught. (Shorter to type. )

Increasing mass was something I did to make the ships more sluggish; that is, less like toy boats in a bathtub. When I say I increased the mass, I increased them over what the RFB 2.0 mod had them. The merchant ship masses I used were at about stock values. I had no way of knowing what their actual mass figures were.

I should note that I decided to use a defined mass, but use 0 for both surface and submerged displacement. It is not necessary to do it this way, but to me this makes the most sense.

[Jeff-Groves]

I've never seen a way to define all Units in a simple way.
Some take tweaking in an area that others don't like.
Any Unit should be tested in Game to get the actions you want.
If anyone can give us the actual math to prove a universal 'Magic Combination'?
I'm all Eyes.

[TorpX]

Originally Posted by Jeff-Groves

I've never seen a way to define all Units in a simple way.
Some take tweaking in an area that others don't like.
Any Unit should be tested in Game to get the actions you want.
If anyone can give us the actual math to prove a universal 'Magic Combination'?
I'm all Eyes.

Well, it depends on what you mean by simple or universal. On some aspects I was able to develop a mathematical guideline, and on others not. For instance, for the relationships of the file parameters and acceleration and speed, I was faced with, perhaps, having to do a series of tests, for each and every vessel in sh4, or develop a formula that I could apply to these vessels. If the number of vessels had not been large, it might have been easier to do the former, but with a large number of ships and subs, I didn't want to rely on trial and error methods.

If the underlying game physics model is any good, we should be able to trust it to a reasonable extent. That is, if we make measured, considered changes to an input, we should obtain rational results (for the most part - I realize the game is far from perfect).

Here is the thread where I discuss/ developed the mod:

http://www.subsim.com/radioroom/show...=211235&page=4

Post #93 is where I give the formula I used.





Fahnenbohn, if you plan on changing many or most of the physics aspects of the ships/subs, I think it is worth looking at. I did not have to do as much work with the ships' stability, as they were, for the most part, pretty good already. The ships that seemed to give the most problems in this area, were the minesweepers; probably because they are very shallow draft.