The BT VehicleData offers similar features and functionality as found in any other of the thinkingParticles data operators. One important difference found in BT VehicleData is, even though it can only handle vehicle data, any particle type can be connected to this operator.  If the particle represents, for example a tractor; parameters related to tractor particles will be active,only. The same is true for wheel particles or trailer particles.

This operator is perfect to procedurally adjust vehicle parameters at any given time. In addition to adjusting vehicle settings, this operator can also be used to query the vehicle status and some interesting physics simulation related status variables.

ON - (Bool) This input data stream determines whether the operator is considered 'on' or 'off'. You can connect other operators to this input channel such as a Bool Helper to activate/deactivate the whole operator.

Time - (Time) This input data stream is used to define the local time for the operator when the user wants to override the default system time.

Particle - (Particle) - This input data stream reads in the currently selected particle group. The data stream MUST be connected and will be highlighted yellow if it is not. Keep in mind a vehicle can be created out of multiple particles.  Every particle can have its own group, or all of the different particle types are in the same group.  

In general, there are three types of special particles: vehicle particles, wheel particles, trailer particles. thinkingParticles takes care about the particle type, there is no need to treat them any different. When the particle input is connected to the operator it will automatically filter particles based on their types.

Wheel Index - to access a specific wheel of the vehicle, feed in an integer value to this input port. A value of zero means accessing the first wheel of the vehicle (tractor) and acquire its data.   

Trailer Index - To access a specific trailer, feed in an integer value to this input port.  A value of zero means accessing the first trailer of the vehicle and acquire its data.

Drive - sets the drive configuration of the vehicle. Front(0), Rear(1), All(2) select one of the options to define the type of drive layout to be used with the vehicles.

Steering - sets the steering wheel angle from -90 to +90 degrees. The slider, found right below this control may also be used to steer the vehicle.

Speed - sets the speed of the vehicle, this value represents a force. Higher numbers will result in a higher speed of the vehicle depending on the ground and friction.

Brake - adds a “breaking force” to the vehicle. The higher this value to stronger the breaking force will be.

Wheel Locked: Front(0),Rear(1),All(2) - select one of those options to activate the hand break. The effect is immediate, unlike the break force which kicks in gradually.

Rotation X,Y,Z - sets the wheel rotational axis in object space. Depending on how the vehicle has been modeled it might be necessary to switch the rotational axis.

Friction Slip -  sets the coefficient of friction between the tire and the ground. Should be about 0.8 for realistic cars, but can easily be increased for better handling. In fact it all depends on the scale of the scene and how the vehicle is modelled.

Rolling Influence - reduces the rolling torque applied from the wheels that might cause the vehicle to roll over. It is a bit of a hack, but it's quite effective. A value of 0.0 means that a roll over will be prevented, 1.0 will act like in the real world and a vehicle actually can roll over.

Suspension Axis X,Y,Z - sets the axis along which the shocks will compress.

Damper Length - defines the length of the shocks. Keep in mind, as always, physics simulations depend heavily on a proper setup of the world.

Damper Stiffness - sets the “stiffness” or overall strength of the shocks. Higher numbers will make the shocks appear much harder.

Damper Relaxation - there are two possible dampening forces at work for the shocks. One force is responsible for counteracting compression of the shocks and one force would work against tension.

Relaxation - sets the counter-force for the relaxation phase of the shocks.

Compression - defines the counter-force for the compression phase of the shocks.

Max Travel -  sets the maximum amount the springs can be compressed at which the shocks will provide their maximum force.

Whenever the suspension cannot support the weight of the vehicle, the wheels may start sinking through the ground. In such cases, increase Stiffness, Max Travel or Length. Increasing the length of the shocks too much might introduce instability into the simulation. Max Travels sets the maximum amount the springs can be compressed at which the shocks will provide their maximum force.

Max Force - sets the maximum force that can be applied to the shocks (when Max Travel is reached).

The output values of this operator are identical to their input counterpart. However, some more variables have been added and those can be used to query about the physics simulation status of the vehicle.

Collision - lets you choose, from the drop down menu, the physics engine solver to use for the rope simulation. All compatible solvers found in the thinkingParticles setup will be automatically listed.