Vehicle speed bounded

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Vehicle speed bounded

Postby blackbird_dream » Thu Mar 15, 2018 10:26 am

In direction y of my Newtonworld the gravity is set to -9.8.
with a script I'm applying a constant force (F=3600*9.8 ) to a simple mass (m=3600) in direction y.
The mass doesn't move. That's fine.

Now in addition I'm applying a constant force (F=6000) in direction z. The mass starts accelerating along z. z.velocity increases but it is bounded by 3.3. It never gets higher than 3.3
Is there default numerical damping ? Can I remove it ?
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Re: Vehicle speed bounded

Postby Sweenie » Thu Mar 15, 2018 11:06 am

Newtonbodies by default have a linear and angular damping of 0.1.
I've added properties to modify this damping now.
LinearDamping & AngularDamping
Also changed function GetCenterOfMass to a property called CenterOfMass instead as you did.
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Re: Vehicle speed bounded

Postby blackbird_dream » Thu Mar 15, 2018 11:07 am

super kind.
I'll test it.
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Re: Vehicle speed bounded

Postby blackbird_dream » Fri Mar 16, 2018 4:54 am

Thks, I've tested it.
There seems nothing happens. It's curious because in my old delphi apps I used the default value of 0.1 without such weird behavior.

I've changed the lineardamping to 0.00001 and nothing changed, the speed was still bounded by 3.3
Here is my simple demo :
https://ufile.io/vzlj2

NB : In my delphi app I used the ASAP mode (other modes :MANUAL, APPLICATIONIDDLE) and fixeddeltatime=0.01
TimeReference: performanceCounter (other types : RTC, EXTERNAL)
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Re: Vehicle speed bounded

Postby blackbird_dream » Fri Mar 16, 2018 5:15 am

It's better when I change the Update Rate to 75 (Initially 120) but is the simulation fidelity rate dependent and how ?
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Re: Vehicle speed bounded

Postby blackbird_dream » Fri Mar 16, 2018 6:39 am

In the same test I'm using a cube moved by gravity whose displacement is computed by NewtonDYnamics
and a second cube updated procedurally (z=1/2 g time^2).
Even at lowest rate (60) and null damping the 2 cubes get away from each other.
Something goes wrong.

the demo here
https://ufile.io/6thc1
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