Selsey I

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[TerryRussell]

Thanks for that, Terry.

So if I understand you correctly, you don't put in 'how a ship will behave under XYZ' you tell the computer 'this ship is x heavy y long z soonandsoforth' and let the computer work out how it actually behaves... The programme is trying to calculate in real time what the ship will do...

Pretty much.


I simplified it somewhat. Each element of the ship's performance has a number of things that describe it. For many of them I have to draw a graph, for instance, there is a graph of change of thrust. So, I have to plot points that control how fast the thrust increases/decreases when you slide the control forwards or backwards (one graph for each direction). It has to account for the speed at which the vessel is going now, where the thrust control was when you started the movement and where it is now. I also have to explain to the computer (by way of graphs/forumlae etc) that the amount of change is further affected by the speed of the ship at each instant.

And that's for a very simple thing: speeding up by pushing the throttle forward.

There are settings for everythng imaginable. How about this:

There are a set of curves for the efect that the waves have as they hit the side of the vessel. This changes according to strength of the waves (of course) as well as the angle at whch they hit and the forward speed of the vessel.

These are in turn affected by the curves that describe the moments of inertia of the vessel in each of 12-ish different ways - linear momentum/inertia, angular momentum/inertia on each axis, and the limiting factors ("damping") in each axis, both linear and angular.

And those are affected by things like the bow resistance, sides resistance, bottom resistance, all of which have their own curves. And so it goes round.

Then factor in the forward speed, rate of acceleration, mass of the vessel, centre of mass, centre of floatation, and all the other stuff.

I am truly amazed that the PC can do this for a single vessel, never mind every vessel, evey buoy, static, AI and player in the environment.

You get to understand why Ship Simulator needs a high-spec PC and why people roll their eyes when they read "Well, I can play {insert name of game} OK on my PC."

Actually, I think this is probably easier to do than to explain.

Maybe....  

[Stuart2007]

I wonder if these calculations are necessary to this degree for the GAME version... PRO, I can understand.

But most SS08 players, if they are honest, probably are only interested in 'what looks good'

[mvsmith]

Terry’s explanation should make it easier to understand why the frame rate gets lower as the number of vessels in a mission increases. Those calculations, or a simplified set, must be performed for every ship in the environment before each frame is rendered.

Those calculations are a leading source of QV crashes with a newton.dll error.

It also helps to explain why the true speed of ships depends upon the frame rate.

[TerryRussell]

I wonder if these calculations are necessary to this degree for the GAME version... PRO, I can understand.

But most SS08 players, if they are honest, probably are only interested in 'what looks good'

If any of them are set wrong, it does make the vessel handle "wrongly". Reading the comments about Virtual Sailor, which has less parameters, the difference in realistic performance does seem to be noticed by even quite young and inexperienced (presumably) players. So I think that if they were reduced, people would notice and comment adversely.

[Stuart2007]

Yes, this is a fair and reasonable point, Doc T.

IMO this is the first proper explanation from ANYONE on the subject. Well done. 

I have to admit that recently re-downloading the 1.4.2 update that the PoR handles much more poorly than the original (I have it on good authority that the original one is more accurate)... I must download your recent amendments and see what they are like...

Well, I shall (for once) shut up on this subject and leave you to it.

[Firestar]

Hi Stu, many people (including myself) have used the old PoR .dyn file in their current version by replacing the original.

[Stuart2007]

Hi Stu, many people (including myself) have used the old PoR .dyn file in their current version by replacing the original.

I didn't realise you could do that... Does it automatically back it up then, or do I have to re-install the CD, back it up, install 1.4.2 and then reinstall the backup??

[jammydodger]

I would have thought there's no backups. Then again it's possible (although it would waste so much space) but you have to know nothing to know anything.

[matt5674]

Terry,
Maybe Selsey III can be the Klipper and Selsey 4 would be the motor Yachts as a thought


And excellent on the Selsey I and the repaints with the names of the editors of the super packs I'll be sailing the "Terry Selsey" from New York to Phi Phi through all of the other ports.

[TerryRussell]

Terry,
Maybe Selsey III can be the Klipper and Selsey 4 would be the motor Yachts as a thought


And excellent on the Selsey I and the repaints with the names of the editors of the super packs I'll be sailing the "Terry Selsey" from New York to Phi Phi through all of the other ports.

I looked at the motor yacht but unfortunately, it really isn't usable. Shame, as it would have been nice to have one like that. I would feel most at home in it.

The Klipper doesn't actually have a wheelhouse... But I have been looking and thinking.

[McGherkin]

Both motor yachts?

[TJK]

HI Terry

Try the inland dry cargo Dortmund or and Classic sail ship- flying Cloud or one of the inlands tanker?

[TerryRussell]

I was hoping to be able to use the Dortmunder, as it is the most complete of all the Inland AIs. But unfortunately, the surfaces are only textured to be viewed from outside. When you go inside, all the surfaces are invisible.

Believe me, I have tried each and every AI vessel, to see if any are possible without disturbing the Vstep developers.

I do have three possible candidates though, and two new vessels. So keep watching the weekly releases!

[matt5674]

I will watch the brilliant coming packs' trails till they come lol