I have added more realistic acceleration to the car, and have added "brakes" with the following code. To use the brakes, just tap the 'x' key while the car is moving and it will feel like you are tapping the brakes - to slam the brakes on, just hold down the 'x' key and watch the car skid to a stop. Replace the NewtonVehicle action in your vehicle_playground.wdl file with this:

Code:

---

action NewtonVehicle
{	
	var car;			
	var forward_flag;
	var reverse_flag;
	var engine_torque;
	
	// save the pointer to the entity as the player
	p_vehicle = my;

	// create the vehicle
	NewtonCreateVehicle (wood_material, VehicleTireEvent, VehicleBeginEvent, VehicleEndEvent);
	
	dll_handle = newtonHandle;	
	car = NewtonGetBody (my);

	// make the car always active
	NewtonSetBodyAutoActiveState (car, 0);
	NewtonSetBodyActiveState (car, 1);
	
	// asign a special force event to the rover
	NewtonSetBodyForceAndTorque (car, VehicleForceEvent);

	my.carSteerTorque = 0.0;
	my.carEngineTorque = 0.0;
	forward_flag = 0.0;
	reverse_flag = 0.0;		
	
	// this is the vehicle control loop;
	while (1) {
	   					
		// read wheel controls
		if(key_a)
		{			
			my.carSteerTorque += .15 * time;	// smoothly turn wheels left			
			if(my.carSteerTorque > 1.0)		// clamp 
			{	my.carSteerTorque = 1.0;	}
		}
		if(key_d)
		{			
			my.carSteerTorque -= .15 * time;	// smoothly turn wheels right
			if(my.carSteerTorque < -1.0)		// clamp
			{	my.carSteerTorque = -1.0;	}
		}
		if(key_w)
		{			
			if(forward_flag == 1.0)
			{	engine_torque = 0.0;
				forward_flag = 0.0;
			}
			reverse_flag = 1.0;											
						
			engine_torque += 10.0 * time;
			if(engine_torque >= my.car_maxToque)
			{	engine_torque = my.car_maxToque;	}
			my.carEngineTorque = engine_torque;
			my.car_topSpeed = engine_torque * 4;
		}
		if(key_s)
		{
			if(reverse_flag == 1.0)
			{	engine_torque = 0.0;
				reverse_flag = 0.0;
			}
			forward_flag = 1.0;									
						
			engine_torque += 10.0 * time;
			if(engine_torque >= my.car_maxToque)	// clamp
			{	engine_torque = my.car_maxToque;	}
			my.carEngineTorque = -engine_torque;	// transfer calculation
			my.car_topSpeed = engine_torque * 4;	// Calc topSpeed based on torque level
		}
		if(key_x)	// Apply brakes
		{	engine_torque -= 10.0 * time;
			if(engine_torque <= 0.0)
			{	engine_torque = 0.0;	}
			
			if(forward_flag == 0.0)	// Car is moving forward
			{	my.carEngineTorque = engine_torque;	}
			if(reverse_flag == 0.0)	// Car is moving in reverse
			{	my.carEngineTorque = -engine_torque;	}					
		}
		
		// Return turned wheels to straight
		if(my.carSteerTorque > 0.0)
		{	my.carSteerTorque -= .05 * time;	}
		if(my.carSteerTorque < 0.0)
		{	my.carSteerTorque += .05 * time;	}		
		
		wait(1);
	}
}   

---

Regards, Ron