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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.<br>
<br>
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. <br>
<br>
Wade / "Starlight Harbour" in Jokaydia, OSgrid, Kitely, Unity, and
Second Life.<br>
<br>
<br>
On 6/7/12 4:30 AM, James Stallings II wrote:
<blockquote
cite="mid:CAOaG_2adJKx7UbweBfjb7LrUBEVO7MfD96fsxPO+tzTCKiiVFA@mail.gmail.com"
type="cite">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'.
<div>
<br>
</div>
<div>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.<br>
<br>
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.</div>
<div><br>
</div>
<div>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.</div>
<div><br>
</div>
<div>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'.</div>
<div><br>
</div>
<div>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.</div>
<div><br>
</div>
<div>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.</div>
<div><br>
</div>
<div>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.</div>
<div><br>
</div>
<div><br>
</div>
<div>Cheers</div>
<div>James aka Hiro Protagonist</div>
<div><br>
</div>
<div><br>
<div class="gmail_quote">On Thu, Jun 7, 2012 at 4:38 AM, Bengt
Falke <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:bengt@falke.nu" target="_blank">bengt@falke.nu</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">This is
getting more and more interesting for each post on the
subject......<br>
<br>
I think it would be a good thing to collect all the relevant
information about physics and scripting in the forum so it
is available to all struggling with this. Are there still
active work going on with ODE or are our only option to find
ways around the problems or hope for the Bullet engine?<br>
<br>
I saw in another post a reference to a OSGrid scripting
forum and I assume it is this section you are referring to
(please correct me if I am wrong): <a
moz-do-not-send="true"
href="http://forums.osgrid.org/viewforum.php?f=5&sid=d584d594240e0917e41480491af385ec"
target="_blank">http://forums.osgrid.org/viewforum.php?f=5&sid=d584d594240e0917e41480491af385ec</a><br>
<br>
That might anyhow be a good place to post in.<br>
Void Pipe<br>
<div class="HOEnZb">
<div class="h5"><br>
<br>
<br>
<br>
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