[Opensim-dev] Questions about Vehicle scripting calls

[James Stallings II]

Any chance you might come introduce yoursel to the dev channel on IRC?
#opensim-dev on the Freenode IRC network.

Cheers

On Thursday, June 7, 2012, Wade Schuette <wade.schuette at gmail.com> wrote:
> If anyone needs the expertise,   I was a math and physics major in
college, am comfortable with various transformations, and can sometimes
provide clues as to how to tackle certain situations -- provided there are
stable tools that do something, anything,  consistently.    After an
initial exploration of vehicle and similar physics in OpenSim and
SecondLife,   and finding behaviors that were not only bizarre, but
unreproducible, or seemed to change by the hour and day,  I just gave up
working on that.
>
> Still, I'm a private pilot and still have all my calculus and mechanics
books and can help with vector or matrix algebra and that sort of thing.
Email me if you have a math / physics question I might be able to help
with, regarding how ACTUAL objects behave in REALISTIC worlds.    I can't
help on why script commands don't do what they should, if you can even
figure out what it was they were hoping to do in the first place.
>
> Wade / "Starlight Harbour"  in Jokaydia, OSgrid, Kitely, Unity, and
Second Life.
>
>
> On 6/7/12 4:30 AM, James Stallings II wrote:
>
> I've been working with vehicle scripting on opensims now for over 4
years. There are lots of historical scripts I have written or adapted from
the work of others, or collaborated on with others in the OSgrid scripting
forums. These include sailing scripts, automobile scripts, and yes, even a
helicopter script. Dave Coyle said over three years ago that my helicopter
was "the most satisfying vehicle he'd ever seen on an opensim'.
> In fact, Owen Oyen and I produced the first vehicles on OSgrid *without
any vehicle functions at all*. These were sailboats that entirely simulated
'sailboat physics' using llSetRot, llGetRot, llApplyImpulse and friends.
The boat was clunky, did not heel, moved in anything but a smooth fashion,
and was hell on the simulation. My more 'modern' boats can be found on
Littlefield region on OSgrid, as well as a historical display documenting
the work on the aquavita. The working copies of the boats are in a vendor;
those sitting at the dock have had the scripts ripped out to reduce lag on
the sim, don't take copies of those.
>
> Later (much later than that boat, the 'Aquavita"), I worked extensively
with Kitto Flora to get ODE implemetations of such vehicle scripting
functions working as  work now. The work is imperfect, but not all of the
problems are with ODE proper; some have to do with various math functions'
implementation in opensim, and how they differ from the same math functions
as implemented in SL under havoc. The short story is, LL's functions are
broken in terms of how physics actually dictates real-world objects behave;
and the same functions are incomplete here, as the developers who worked on
them refused to implement the broken math, and no resolution could be
reached among the devs as to how to proceed, so the functions on opensims
are incomplete and/or unfinished.
> All of this is more or less ancient history. I've got many very simple
test objects needed to reproduce these errors as test cases in inventory on
the grid, and related mantis entries filed, but quite frankly they've been
ignored for so long I lost interest a couple years back and haven't really
bothered with vehicles since. Who wants to sail a boat that doesn't heel?
Who want's to fly an airplane that has no inertia if a vector component is
on the z-axis? Not to mention, incoming physics 'fixes' often break the
workarounds, with no explanation of how to take advantage of the
improvements.
> It's really discouraging to be told about your now non-functional
helicopter you've been using for most of a year that 'those vehicle
functions never really worked anyway'.
> One of the problems is that to make something work you have to be able to
define 'working' in a manner that lends itself to implementation by nuts
and bolts coders, and (so far) no one has presented themselves that has
that sort of exhaustive knowledge of LL's vehicle physics.
> I'm not a nay-sayer; I really hope this stuff can be made to work
someday; but I long ago lost hope as I'll likely be dead and buried before
it happens at current rates of development, especially if everyone forgets
or ignores all the prior work that has been done or that the issues raised
are not so new as the users encountering them.
> I'm available to help with this, as much or as little as is needed, but
you'll have to be patient with me as, at this point, I've largely forgotten
a lot of what I knew about this, having given up on going blue in the face
trying to get anyone to take notice of the issues I was raising.
>
> Cheers
> James aka Hiro Protagonist
>
> On Thu, Jun 7, 2012 at 4:38 AM, Bengt Falke <bengt at falke.nu> wrote:
>
> This is getting more and more interesting for each post on the
subject......
>
> I think it

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