cartoon short-strand orientations unstable over trajectory

[Elaine Meng]

Obvserved during morphing but I don't think the source of the trajectory matters much, since the backbone atom orientations are quite steady but the cartoon representation is flapping around for strands, and only the short ones (3 residues?). I.e. the actual peptide bonds appear to be changing very little in orientation, so I suspect some problem with calculating transverse ribbon orientation for those short guys.

I attach a script to create the morph trajectory and show backbone atoms with transparent ribbons. The morph can be played back with:

coordset #3 0,20 pause 10
-or (to recompute secondary structure at each frame)-
coordset #3 0,20 pause 10 compute t

The latter makes a few strands longer so they don't flap, but the shorter ones still flap.

[Conrad Huang]

Fixed in 0a1121f6.

Strands shorter than 4 residues are not longer smoothed.

[Eric Pettersen]

Milestone renamed