When I take a few rectilinear landscape images and stitch them using Hugin into a cylindrical projection, I get straight segments with sharp bends at the overlap:
Notice the top and bottom of the windshield, and the double-yellow line seen out the windshield.
In contrast, when I take many heavily-overlapping portrait shots, I get nice smooth results:
Given the sparse landscape input, is there a way with Hugin—or any other stitching software—to get it to warp the original images consistently to get output like the latter?
Background motivation: I'm about to be producing video from within a vehicle similar to what you see above, and I'd like to use as few cameras as possible. The test shots above were done with an iPhone (rectilinear ~60° HFoV) while the real video will be shot with a GoPro (mild fisheye ~120° HFoV) so perhaps the result won't be as bad as I fear.