private float CalcSegmentLengthAccurate(SplinePoint3D a, SplinePoint3D b, int approximateCount)
{
var length = 0f;
var transform = GlobalTransform;
var prevPosition = transform.TransformVector(a.Position);
for (int i = 1; i < approximateCount; i++)
{
var currentPosition = Interpolate((float)i / approximateCount, a, b).Translation;
length += (currentPosition - prevPosition).Length;
prevPosition = currentPosition;
}
length += (transform.TransformVector(b.Position) - prevPosition).Length;
return(length);
}
private Matrix44 Interpolate(float amount, SplinePoint3D point1, SplinePoint3D point2)
{
var transform = GlobalTransform;
var position1 = transform.TransformVector(point1.Position);
var position2 = transform.TransformVector(point2.Position);
Vector3 position, direction;
if (point1.Interpolation == SplineInterpolation.Linear)
{
position = Mathf.Lerp(amount, position1, position2);
direction = position2 - position1;
}
else
{
var tangent1 = position1 + transform.TransformNormal(point1.TangentA);
var tangent2 = position2 + transform.TransformNormal(point2.TangentB);
position = Mathf.BezierSpline(amount, position1, tangent1, tangent2, position2);
direction = Mathf.BezierTangent(amount, position1, tangent1, tangent2, position2);
}
return(CalcRotationMatrix(direction, Vector3.UnitY) * Matrix44.CreateTranslation(position));
}
