vehicle slip problem

i have built a wheelchair, one problem my tires slip to much, i just want almost no slip

i tried with tire->setLongitudinalSlipCoefficient(..) but is has no effect?
where do you put this code (in the userCallback() ??)
should i use different functions (e.g. setMaxSideSlipSpeed)

could the sollution be de define the materials id's ??

yeah... make the friction between the wheelchair material and the world material higher (like 2.0)... this will greatly increase the traction of the tires.

1)how do i use Body->setMaterialGroupID(...) for the tires (OgreNewt::Vehicle::Tire) ?

if have no body for the tires ?

2) matPairRolstoelVloer = new OgreNewt::MaterialPair(m_World, matIDRolstoel, matIDVloer);
matPairRolstoelVloer->setDefaultFriction(2.0,1.;

is it necessary to put this code somewhere special ?
is that enough or do i need callbacks?

maybe i could use m_World->getDefaultMaterialID() for the tires,
but my materialpair doenst have any affect

the tires are the same material as the RigidBody that makes the vehicle chassis. they are treated like members of a compound collision, as part of the main rigid body of the chassis.

i tried with m_chassis->setMaterialGroupID(..) doenst work

but i found a sollution, the last parameter of the constructor of OgreNewt::Vehicle::Tire is "collision ID used to determine collision in material callbacks" so that problem is probably solved

but i cant get the material pair working (errors while starting ogre)

in demo 3 (OgreNewt) they use a Callback class,

my questions:
1)do i need i Callback class for the use of OgreNewt::MaterialPair
2)how does this Callback class looks like (and could i get information somewhere)
3)do i need to override functions from this Callback class
4)could it be something else why my code for the OgreNewt::MaterialPair
doesnt work

thx for help

you only need a callback if you want advanced information. to just change the default friction, you don't need a callback.

but if you want to make a callback, yes you need to inherit from the OgreNewt::ContactCallback class, and create your own userBegin() userProcess() and userend() functions.

i can debug but if i start the program i get an error

this is my code
in OgreNewtonApplication.h:
const OgreNewt::MaterialID* matIDLevel;
const OgreNewt::MaterialID* matIDWielen;
OgreNewt::MaterialPair* matPairLevelWielen;

in OgreNewtonApplication.cpp:
matIDWielen = 0; // the tires have collision ID 0
matIDLevel = new OgreNewt::MaterialID( m_World );
matPairLevelWielen = new OgreNewt::MaterialPair( m_World, matIDWielen, matIDLevel );
matPairLevelWielen->setDefaultFriction(0.8,0.;

level1Body->setMaterialGroupID(matIDLevel);


with the 'search error' facility it point to matPairLevelWielen->setDefaultFriction(0.8,0.;

matIDWielen = 0; // the tires have collision ID 0

this line is wrong. you need to make a material here:

matIDWielen = new OgreNewt::MaterialGroupID(m_World);

and make sure you apply that material to the vehicle chassis.