// ----------------------------------------------------------------------------
// alternate version: keep FORWARD parallel to velocity, adjust UP according
// to a no-basis-in-reality "banking" behavior, something like what birds and
// airplanes do
// XXX experimental cwr 6-5-03
public void regenerateLocalSpaceForBanking(Vector3 newVelocity, float elapsedTime)
{
// the length of this global-upward-pointing vector controls the vehicle's
// tendency to right itself as it is rolled over from turning acceleration
Vector3 globalUp = new Vector3(0, 0.2f, 0);
// acceleration points toward the center of local path curvature, the
// length determines how much the vehicle will roll while turning
Vector3 accelUp = _smoothedAcceleration * 0.05f;
// combined banking, sum of UP due to turning and global UP
Vector3 bankUp = accelUp + globalUp;
// blend bankUp into vehicle's UP basis vector
float smoothRate = elapsedTime * 3;
Vector3 tempUp = up();
tempUp = OpenSteerUtility.blendIntoAccumulator(smoothRate, bankUp, tempUp);
tempUp.Normalise();
setUp(tempUp);
// annotationLine (position(), position() + (globalUp * 4), gWhite); // XXX
// annotationLine (position(), position() + (bankUp * 4), gOrange); // XXX
// annotationLine (position(), position() + (accelUp * 4), gRed); // XXX
// annotationLine (position(), position() + (up () * 1), gYellow); // XXX
// adjust orthonormal basis vectors to be aligned with new velocity
if (speed() > 0)
{
regenerateOrthonormalBasisUF(newVelocity / speed());
}
}
// ----------------------------------------------------------------------------
// apply a given steering force to our momentum,
// adjusting our orientation to maintain velocity-alignment.
public void applySteeringForce(Vector3 force, float elapsedTime)
{
Vector3 adjustedForce = adjustRawSteeringForce(force); //, elapsedTime);
// enforce limit on magnitude of steering force
//Vector3 clippedForce = adjustedForce.truncateLength (maxForce ());
//Vector3 clippedForce = adjustedForce.truncateLength(maxForce());
Vector3 clippedForce = truncateLength(adjustedForce, maxForce());
// compute acceleration and velocity
Vector3 newAcceleration = (clippedForce / mass());
Vector3 newVelocity = velocity();
// damp out abrupt changes and oscillations in steering acceleration
// (rate is proportional to time step, then clipped into useful range)
if (elapsedTime > 0)
{
float smoothRate = OpenSteerUtility.clip(9 * elapsedTime, 0.15f, 0.4f);
_smoothedAcceleration = OpenSteerUtility.blendIntoAccumulator(smoothRate,
newAcceleration,
_smoothedAcceleration);
}
// Euler integrate (per frame) acceleration into velocity
newVelocity += _smoothedAcceleration * elapsedTime;
// enforce speed limit
//newVelocity = newVelocity.truncateLength (maxSpeed ());
newVelocity = truncateLength(newVelocity, maxSpeed());
// update Speed
setSpeed(newVelocity.Length);
// Euler integrate (per frame) velocity into position
setPosition(Position + (newVelocity * elapsedTime));
// regenerate local space (by default: align vehicle's forward axis with
// new velocity, but this behavior may be overridden by derived classes.)
regenerateLocalSpace(newVelocity); //, elapsedTime);
// maintain path curvature information
measurePathCurvature(elapsedTime);
// running average of recent positions
_smoothedPosition = OpenSteerUtility.blendIntoAccumulator(elapsedTime * 0.06f, // QQQ
Position,
_smoothedPosition);
}
// ----------------------------------------------------------------------------
// measure path curvature (1/turning-radius), maintain smoothed version
void measurePathCurvature(float elapsedTime)
{
if (elapsedTime > 0)
{
Vector3 dP = _lastPosition - Position;
Vector3 dF = (_lastForward - forward()) / dP.Length;
//SI - BIT OF A WEIRD FIX HERE . NOT SURE IF ITS CORRECT
//Vector3 lateral = dF.perpendicularComponent (forward ());
Vector3 lateral = OpenSteerUtility.perpendicularComponent(dF, forward());
float sign = (lateral.DotProduct(side()) < 0) ? 1.0f : -1.0f;
_curvature = lateral.Length * sign;
//OpenSteerUtility.blendIntoAccumulator(elapsedTime * 4.0f, _curvature,_smoothedCurvature);
_smoothedCurvature = OpenSteerUtility.blendIntoAccumulator(elapsedTime * 4.0f, _curvature, _smoothedCurvature);
_lastForward = forward();
_lastPosition = Position;
}
}