[Opensim-dev] Questions about Vehicle scripting calls

[Bengt Falke]

Does anybody know what kind of physics Avination use? Physics works better there if I remember correctly?
Void Pipe

6 jun 2012 kl. 19:10 skrev James Hughes:

> I have been experimenting with trains in SL and would like to make a physical one that works in OpenSim. Hopefully these cases aren't some limitation of the physics engines and can have a proper fix.
> 
> -BlueWall
> 
> On 06/05/2012 07:46 PM, Mike Higgins wrote:
>> I was talking to Justin Clark-Casey at the OpenSim developers meeting
>> this morning, and he suggested that the mailing lists would be the
>> easiest way to have a conversation about vehicle physics on OpenSim.
>> Justin you there? Is this where you meant? Anyone else want to talk
>> about vehicle scripting in OpenSim?
>> 
>> I am in the process of testing the OpenSim vehicle scripting calls and
>> trying to find out what works and what can be worked around. I am
>> submitting mantis reports when I think I see a true bug, issue numbers
>> 0006039 <http://opensimulator.org/mantis/view.php?id=6039> and 0006040
>> <http://opensimulator.org/mantis/view.php?id=6040> for starters. Instead
>> of submitting 1000 line vehicle scripts that do not work, I am writing
>> small 10-line scripts that demonstrate a particular problem.
>> 
>> Issue 0006040 <http://opensimulator.org/mantis/view.php?id=6040> is
>> particularly interesting because if my hypothesis is correct, the linear
>> motor direction is being actively projected onto the global XY plane. I
>> cannot get an airplane to glide up, or a balloon to rise using the
>> linear motor. (Hover height works with balloons, but not the linear
>> motor even with hover height disabled). The interesting thing about this
>> is that my hypothesis suggests that there is extra code doing this
>> projection onto the XY plane. I checked the vehicle flags and there
>> isn't one that should force this extra projection into the calculations.
>> Vehicle type balloon is supposed to have all the flags removed, but just
>> to be sure I used the remove call to clear them all. The linear motor
>> still cannot go up. Can someone familiar with the code look at the
>> linear motor and tell me why this is happening and if there is a way to
>> disable it? (I tried turning flags like VEHICLE_FLAG_NO_DEFLECTION_UP on
>> to see if this flag was inverted, and if it applied to the motor instead
>> of deflection, but no luck).
>> 
>> The fun thing is that I can write one kind of vehicle that works well --
>> assuming this bug is there. I built a vehicle that has the linear motor
>> set to <0,0,20>, pointing straight up. When the vehicle is perfectly
>> horizontal, the projection of this motor onto XY is <0,0,0> and the
>> vehicle does nothing. But then when you tilt the vehicle in any
>> direction, the projection of the linear motor on XY becomes non-zero and
>> causes it to start moving in the direction of tilt. This feels a lot
>> like an RL helicopter, so I used the control keys to pitch down/up to
>> move forward/backwards, added yaw left and right, and used page-up/down
>> to increase/decrease the hover height. I put it in a hacked together
>> helicopter build and it is a lot of fun!
>> 
>> I'm looking for work-arounds for the current vehicle routine behaviors.
>> One work-around for an airplane is to turn on hover height, check the
>> airplane speed and pitch once a second in timer(), calculate what
>> altitude the plane should get to in the next second, and set hover
>> height to that altitude. The things we do to get stuff working!
>> 
>> 
>> 
>> 
>> 
>> _______________________________________________
>> Opensim-dev mailing list
>> Opensim-dev at lists.berlios.de
>> https://lists.berlios.de/mailman/listinfo/opensim-dev
> 
> _______________________________________________
> Opensim-dev mailing list
> Opensim-dev at lists.berlios.de
> https://lists.berlios.de/mailman/listinfo/opensim-dev
>