yellow polyline is pointing different points as the scene changes.
down here is the way i found the vector.
calculate quaternion from heading-pitch-roll (transforms.headingpitchrollQuaternion)
and then find it’s matrix.
the unit vectors(x, y, z) is multiplied by the matrix.
final, add the multiplied values to each position.
A line floating above the Earth will look like it changes what it is pointing at because of perspective. Rotating the camera around the polyline sandcastle shows this. Is that what you are seeing with your line?
Would you be able to provide a minimal sandcastle to help us help you better?
