forward motion car physics - gradual slow
- by spartan2417
Im having trouble creating realistic car movements in xna 4.
Right now i have a car going forward and hitting a terminal velocity which is fine but when i release the up key i need to the car to slow down gradually and then come to a stop.
Im pretty sure this is easy code but i cant seem to get it to work
the code - update
if (Keyboard.GetState().IsKeyDown(Keys.Up))
{
double elapsedTime = gameTime.ElapsedGameTime.Milliseconds;
CalcTotalForce();
Acceleration = Vector2.Divide(CalcTotalForce(), MASS);
Velocity = Vector2.Add(Velocity, Vector2.Multiply(Acceleration, (float)(elapsedTime)));
Position = Vector2.Add(Position, Vector2.Multiply(Velocity, (float)(elapsedTime)));
}
added functions
public Vector2 CalcTraction()
{
//Traction force = vector direction * engine force
return Vector2.Multiply(forwardDirection, ENGINE_FORCE);
}
public Vector2 CalcDrag()
{
//Drag force = constdrag * velocity * speed
return Vector2.Multiply(Vector2.Multiply(Velocity, DRAG_CONST), Velocity.Y);
}
public Vector2 CalcRoll()
{
//roll force = const roll * velocity
return Vector2.Multiply(Velocity, ROLL_CONST);
}
public Vector2 CalcTotalForce()
{
//total force = traction + (-drag) + (-rolling)
return Vector2.Add(CalcTraction(),
Vector2.Add(-CalcDrag(), -CalcRoll()));
}
anyone have any ideas?
