Sea State & Ship Motion

[iambecomelife]

I have always been concerned about how much the SH3 ships roll and pitch, even when they are in calm seas. I have been trying to find some trigger affecting ship mass that will keep the larger vessels nearly motionless until there is a violent storm/heavy sea state. Does anyone know what to do in order to achieve this? Adjusting the MASS and DISPLACEMENT values in the sim file does not seem to help very much.

Thanks.

Adjust the gc_center in the sim up or down.
To high and a ship will roll-over.
Set very low and a unit is more stable.
You can also adjust the fr-ratio
.5 is the center of the unit.

[linerkiller]

Originally Posted by iambecomelife

I have always been concerned about how much the SH3 ships roll and pitch, even when they are in calm seas. I have been trying to find some trigger affecting ship mass that will keep the larger vessels nearly motionless until there is a violent storm/heavy sea state. Does anyone know what to do in order to achieve this? Adjusting the MASS and DISPLACEMENT values in the sim file does not seem to help very much.

Thanks.

Good point IABL.
Destroyers are too stable and fast in rough seas, according to seamen's descriptions they should dance like tuna cans...and surely, any speed exceeding 20 knots would surely rip them apart

There is also drag LR and UD in the sim
The amount of drag left - right, up - down

If you need the reference from the SH3sim.act file?
I can post it.

[iambecomelife]

Originally Posted by privateer

There is also drag LR and UD in the sim
The amount of drag left - right, up - down

If you need the reference from the SH3sim.act file?
I can post it.

Thanks. I already did some stuff with the drag values but it produced bizarre sailing behavior with the ships pitching violently. I will try manipulating the fr ration to see what happens.

[Subtype Zero]

IABL--

I have also been working on the pitch and roll of various ships, but mainly to prevent the tendency of some ships (tramp steamers, Granville type freighters, LST's, etc.) from sinking in heavy seas. See my brief thread on this topic here: http://www.subsim.com/radioroom/showthread.php?t=138180 I think I have made some significant progress in this area and I hope to update my STzTrampSteamerFix mod sometime later today.

Privateer is correct, of course, about the function of values such as gc_height and fr_ratio. Lower gc_height to get a more stable ship (less roll). I think you can also get more stable behavior by altering the mass and surfaced_displacement values as you indicated you have already tried. Usually, lowering mass results in the ship sitting higher in the water--try the opposite in order to get it to sit lower (you may also have to increase surfaced_displacement to help achieve the effect of a heavier ship). I have also had some success altering pitch with fr_ratio, which seems to be set to a default of .5 for all ships.

I have not tried altering LR or UD drag yet, as I did not know what those values did! Thanks, Privateer, for shedding light on that! I will investigate what effect those values have on the changes I have already made on my ships later today.

[Subtype Zero]

IABL--
How much up or down did you alter the UD drag values? I'm trying to guess a good starting point for changing those values.