static Vector3 CalcNewVelocity(float minSpeed, Vector3 curVel, Vector3 dsrVel, Vector3 defaultVelocity)
{
//We have to take into account that bird can't change their direction instantly. That's why
//dsrVel (desired velocity) influence first of all on flying direction and after that on
//velocity magnitude oneself
var curVelLen = curVel.magnitude;
if (curVelLen > MathTools.epsilon)
{
curVel /= curVelLen;
}
else
{
curVel = defaultVelocity;
curVelLen = 1;
}
var dsrVelLen = dsrVel.magnitude;
var resultLen = minSpeed;
if (dsrVelLen > MathTools.epsilon)
{
dsrVel /= dsrVelLen;
//We spend a part of velocity magnitude on bird rotation and the rest of it on speed magnitude changing
//Map rotation to factor [0..1]
var angleFactor = MathTools.AngleToFactor(dsrVel, curVel);
//If dsrVel magnitude is twice bigger than curVelLen then bird can rotate on any angle
var rotReqLength = 2 * curVelLen * angleFactor;
//Velocity magnitude remained after rotation
var speedRest = dsrVelLen - rotReqLength;
if (speedRest > 0)
{
curVel = dsrVel;
resultLen = speedRest;
}
else
{
curVel = Vector3.Slerp(curVel, dsrVel, dsrVelLen / rotReqLength);
}
if (resultLen < minSpeed)
{
resultLen = minSpeed;
}
}
return(curVel * resultLen);
}
//Force which attracts birds to waypoints
static Vector3 CalculateAttractionForce(Settings sts, Vector3 curPos, Vector3 curVelocity)
{
if (!sts.Trace)
{
return(Vector3.zero);
}
var attrPos = sts.Trace.GetAtractionPoint();
var direction = (attrPos - curPos).normalized;
//The force have an effect only on direction and shouldn't increase speed if bird flies in the right direction
var factor = sts.AttractrionForce * sts.SpeedMultipliyer * MathTools.AngleToFactor(direction, curVelocity);
return(factor * direction);
}
public bool Calc(Vector3 cur, Vector3 birdDir, Collider cld, out Force force)
{
var pointOnBounds = MathTools.CalcPointOnBounds(cld, cur);
var revDir = cur - pointOnBounds;
var dist = revDir.magnitude;
if (dist <= MathTools.epsilon)
{
//Let's setup the direction to outside of colider
revDir = (pointOnBounds - cld.transform.position).normalized;
//and distance to N percent of OptDistance
dist = 0.1f * optDistance;
}
else
{
revDir /= dist;
}
//Force depends on direction of bird: no need to turn a bird if it is flying in opposite direction
force.dir = revDir * (CalcImpl(dist) * MathTools.AngleToFactor(revDir, birdDir));
force.pos = pointOnBounds;
return(true);
}