private void FixedUpdate()
{
Vector3 pointVelocity = body.GetPointVelocity(transform.position);
Vector3 airVelocity = Vector3.zero;
Vector3 localFlow = transform.InverseTransformDirection(airVelocity - pointVelocity);
airSpeed = -localFlow.z;
airDensity = AirDensitySetting.getDensity(transform.position.y);//1.225f
rpm = maxRPM * throttle;
float rotationSpeed = rpm / 30 * Mathf.PI;
//suppose rpm is large enough so aoa is small enough that outflow speend is just geometricalSpeed
//also suppose
geometricalSpeed = rpm / 60 * pitch;
float area = Mathf.PI * diameter * diameter / 4;
thrust = airDensity * area * 2 * geometricalSpeed * (geometricalSpeed - airSpeed);
//thrust can be lesser than zero
dragTorque = thrust * pitch / (2 * Mathf.PI) / propellerEfficiency * -rotationDirection * dragTorqueCoefficient;
Vector3 angularMomentum = rotationSpeed * propellerInertia * rotationDirection * transform.forward;
Vector3 precessionTorqueVector = -Vector3.Cross(body.angularVelocity, angularMomentum);
precessionTorque = precessionTorqueVector.magnitude;
Vector3 totalTorque = precessionTorqueVector + dragTorque * transform.forward;
body.AddForceAtPosition(transform.forward * thrust, transform.position);
body.AddTorque(totalTorque);
}
private void FixedUpdate()
{
Vector3 foilVelocity = body.GetPointVelocity(transform.position);
Vector3 airVelocity = Vector3.zero;
Vector3 localFlow = transform.InverseTransformDirection(airVelocity - foilVelocity);
localFlow.x = 0;
planarFlowSpeed = localFlow.magnitude;
float planarFlowSpeed1 = Mathf.Clamp(planarFlowSpeed, 0, maxSpeed);
angleOfAttack = planarFlowSpeed > 0 ? -Mathf.Atan2(-localFlow.y, -localFlow.z) * Mathf.Rad2Deg : 0;
airDensity = AirDensitySetting.getDensity(transform.position.y);//1.225f
//float coeff1 = 0.5f * airDensity * planarFlowSpeed * planarFlowSpeed * chordLength*sectionLength;
float coeff2 = 0.5f * airDensity * planarFlowSpeed1 * planarFlowSpeed1 * chordLength * sectionLength;
drag = dragCoefficient.Evaluate(angleOfAttack) * coeff2;
lift = liftCoefficient.Evaluate(angleOfAttack) * coeff2;
Vector3 localForce = Quaternion.Euler(angleOfAttack, 0, 0) * new Vector3(0, lift, -drag);
force = transform.TransformDirection(localForce);
force = oldForce = Vector3.Lerp(oldForce, force, Time.fixedDeltaTime / (damping + Time.fixedDeltaTime));
body.AddForceAtPosition(force, transform.position);
Debug.DrawRay(transform.position, transform.TransformDirection(localFlow).normalized, Color.blue);
Debug.DrawRay(transform.position, transform.TransformDirection(localForce), Color.green);
Debug.DrawRay(body.position, body.velocity.normalized, Color.red);
}
public static float getDensity(float height)
{
if (!singleton)
{
var go = new GameObject("AirDensitySetting");
singleton = go.AddComponent <AirDensitySetting>();
}
return(Mathf.Min(singleton.maxDensity, singleton.seaLevelDensity * Mathf.Pow(0.5f, height / singleton.halfDensityHeight)));
}
private void Start()
{
singleton = this;
}