Determining a smoothly changing curve normal direction is not a trivial task. In recent Slicer versions, we introduced curve node, which can provide curve tangent and normal using Frenet-Serret frame.
Here is a complete example of computing a panoramic X-ray from a cone-beam dental CT. Just a demonstration of how an image can be resampled along a curve - the code is not optimized for performance or quality and distance along curve is not scaled (we simply used all point indices instead of retrieving point indices based on desired distance along curve).
