Do the Pano13 tilt parameters TiX, TiY, TiZ and TiS exist in some form in Hugin or only in libpano13?
What are they tilting?
Looking at the code, I can't backtrack from implementation to intent.
They are effectively lens parameters, right?
I am thinking in terms of a division between lens parameters and "camera?" parameters:
The former is all part of the mapping between an x,y pixel position in the image and a correct yaw,pitch relative angle (direction of the obect that pixel imaged relative to the direction the camera is pointing).
The latter is involved in mapping from that correct relative yaw,pitch to the true location (in some coordinate system) of that object. Computing the actual direction by combining the camera's yaw, pitch, roll with that relative yaw,pitch. Combining that with the camera's X,Y,Z location (TrX, TrY, TrZ) to compute the line of sight. Intersecting that line of sight with something to determine the object seen.
I'm investigating rewriting parts of libpano13 for various possible benefits for hugin++. My first impulse is to leave out TiX, TiY, TiZ and TiS. But if that would be a bad idea, I hope someone will tell me why. If I don't leave them out, I'd really like to understand them better before including them.
That "Intersecting" step is something I want to provide an alternate version of. The rest, I'd like to match behavior but with new code.