private static async Task <MapPoint> CreatePointAlongArc(MapPoint startPt, MapPoint endPt, MapPoint centerPt, double angle, double radius, SpatialReference spatRef, bool arcIsMinor, bool arcIsCounterClockwise)
{
System.Windows.Media.Media3D.Vector3D start = new System.Windows.Media.Media3D.Vector3D(startPt.X - centerPt.X, startPt.Y - centerPt.Y, startPt.Z - centerPt.Z);
System.Windows.Media.Media3D.Vector3D end = new System.Windows.Media.Media3D.Vector3D(endPt.X - centerPt.X, endPt.Y - centerPt.Y, endPt.Z - centerPt.Z);
System.Windows.Media.Media3D.Vector3D normalOfPlane = new System.Windows.Media.Media3D.Vector3D();
normalOfPlane = System.Windows.Media.Media3D.Vector3D.CrossProduct(start, end);
//Two ortho vectors: orthoVec and start
System.Windows.Media.Media3D.Vector3D orthoVec = new System.Windows.Media.Media3D.Vector3D();
orthoVec = System.Windows.Media.Media3D.Vector3D.CrossProduct(normalOfPlane, start);
//If this is not done then half of the keyframes for S-shaped curve are not on the curve
if (arcIsMinor && !arcIsCounterClockwise)
{
orthoVec.Negate();
}
//Normalize
start.Normalize();
orthoVec.Normalize();
System.Windows.Media.Media3D.Vector3D ptAlong = new System.Windows.Media.Media3D.Vector3D();
ptAlong = radius * Math.Cos(angle) * start + radius * Math.Sin(angle) * orthoVec;
MapPoint intermediateKeyframePoint = await QueuedTask.Run(() => MapPointBuilder.CreateMapPoint(ptAlong.X + centerPt.X, ptAlong.Y + centerPt.Y, ptAlong.Z + centerPt.Z, spatRef));
return(intermediateKeyframePoint);
}
