For craft at sea level over non land turbulence equations could be modified to create rythmic up down motion as well as "currents" from a direction.
If the frequency of the verticla turbulence shift is equal to the speed of the ship times 3 to 20 feet it should provide reasonable wave dip. On Sat, 3 Jun 2006 7:57 am, Jeff Koppe wrote: > As a long time Virtual Sailor user/idea contributor this thread caught > my attention (well... once it said "Sailing Ships..." in the subject). > In fact I've been toying with the idea of attempting to make my own > cross-platform sailing simulator for several years. I had thought about > using FG as a starting point but more recently I decided Delta3d would > suit my needs better. But then again I'm primarily a Perl programmer > and it's all vaporware at this point! If there is any movement in this > direction I'd be more than happy to help. I'd gladly convert any of my > Virtual Sailor boats for use and probably build anything needed. (See > www.static-lift.net for examples.) But I do think that wave action upon > a boat is THE key to a sailing/boating/ship simulator. Let's face it, > regardless of the motive power of the vessel (I too, had downloaded the > original Surprise program with the intent of porting it over to Linux), > moving up, down, across and through waves is the defining factor of ma > ritime travel. > > --jeff > > >> ----- Original Message ----- >> From: "Steve Hosgood" <[EMAIL PROTECTED]> >> To: [EMAIL PROTECTED], "FlightGear developers discussions" >> <flightgear-devel@lists.sourceforge.net> >> Subject: Re: [Flightgear-devel] Sailing Ships (was Re: Tides in >> FlightGear?) >> Date: Fri, 02 Jun 2006 09:49:04 +0100 >> >> >> GWMobile wrote: >> >> > What about changing the aerodynamic computation so they take >> > place based on radius from the earth and at what would be sea >> > level change the air density to that of water. >> > Then any object below sealevel "flys under those equations. It >> > would allow for surface ships and submarines. >> > >> > And load in the whole terrain map of the world including all >> > bathespheric data >> > >> > >> > >> >> I'd considered this, but I don't have the knowledge of hydraulics >> necessary to try and "parameterise" a ship's behaviour to suit (say) >> jsbsim. I think we'd need to spend some time running model hulls >> through >> water tanks or flumes if we were ever to gain that sort of data, and >> that means waiting until some Ph.D ship design students fancy getting >> into the project! >> >> I'm thinking more modestly for now, i.e take Peter Davis's "surprise" >> FDM as a starting point. It doesn't handle any of the flotation >> aspects >> of a ship - just assumes the ship is at water level (which is OK until >> you want to try handling behaviour in waves). Davis's sim basically >> deals with thrust on sails up masts at various heights with yardarms >> set >> at given angles. Oh, and a rudder of course. It does consider heeling >> though, and in a true "FDM" for a ship I believe a heeled-over hull >> (as >> long as it is moving) is a significant contribution to being able to >> steer the thing. I've not dug in deep enough to see if Davis deals >> with >> heeling effects using real data or just fudge-factors. >> >> Either way, I think it'll be OK for a starter. >> >> FG's world model doesn't even need bathymetric data to start with. >> Basically you could get away with "if (ship within 50m of land) then >> you've run aground;" as a starting point. Worry about bathymetrics >> *after* getting the rest of it to work. >> >> But you're right about submarines of course. They do fly in the water. >> Boats are the special case. >> Steve. >> >> >> >> _______________________________________________ >> Flightgear-devel mailing list >> Flightgear-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/flightgear-devel > >> > > > -- > _______________________________________________ > Surf the Web in a faster, safer and easier way: > Download Opera 8 at http://www.opera.com > > Powered by Outblaze > > > _______________________________________________ > Flightgear-devel mailing list > Flightgear-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/flightgear-devel Bush's family and their Saudi partners make higher profits by preventing Saddam's huge Iraqi oil reserves from ever being sold. They'll Enron the world - George Watson 2001 For Hurricanes www.globalboiling.com For solar wind and earthquakes www.electricquakes.com Typos caused by two inch mobile phone keyboard _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
