btRaycastVehicle: vibration (braking while vehicle stopped)

[gjaegy]

Hi,

I am encountering an issue, which is easily reproducible with the vehicle demo.
Simply apply brake to each of the 4 wheels (instead of applying them to the rear wheels only), so simply add these two lines in VehicleDemo.cpp, in clientMoveAndDisplay():

Code: Select all

m_vehicle->setBrake(gBreakingForce,0);
m_vehicle->setBrake(gBreakingForce,1);

The effect can be magnified by increasing the "maxBreakingForce" constant value to 1000.0. Attached the modified "VehicleDemo.cpp" file.

Now simply press the up arrow key (accelerate) for a few second, then release the key, then press the down arrow key (brake) until the vehicle stops. You will see the vibration effect quite noticeably.

[*]first question: am I supposed to apply braking to two wheels only ?
[*]second question: I guess the issue comes from the calcRollingFriction() function, which returns a non-zero friction, which oscilates each frame. Any idea how I can fix this ?

Thanks,
Greg

[gjaegy]

nobody ?

[Erwin Coumans]

I have a lot of other things to care about right now, but I'll deal with the issue.

Thanks for reporting it in the issue tracker!
Erwin

[gjaegy]

Thanks to you, Erwin

[Empire-Phoenix]

So, after a little more than a year, might I try to bump this?

In reference to this:
http://hub.jmonkeyengine.org/forum/topi ... ost-261882
where a possible solution and a more detailed explanation is provided.

[gjaegy]

it's never too late
I will have a look at your suggestion, once I get some time. Thanks for sharing it here !