ReSpeed keyframe Timings

respeedKeyframeTimings_v001.py

'''
Problem:
keyframes from camera tx, ty, tz, rx, ry, rz ranging from 1001 to 1195
need to have their timing remapped, such that the new timing is sped up by 2x
thus, the formula where kT = original frame, is ((kT - 1001) * 0.5) + 1001
This will give us new keyframes from frames 1001 - 1098.

New frame range after re-speed is 1001 - 1093, we just truncate frames 1094 - 1098.
'''

from pymel.core import *

kfList = listConnections('VFX_0081_8220_Cam', plugs=False, type='animCurve')
for kf in kfList:
    print ('kf is {}'.format(kf))
    # keyframe(kf, q=True, a=True, tc=True, vc=True) gets a list of key time/value tuples.
    for idx, k in enumerate(keyframe(kf, q=True, a=True, tc=True, vc=True)):
        print 'idx is {}, keyframe is {}'.format(idx, repr(k))
        kTime = k[0]
        kTimeNew = ((kTime - 1001) * 0.5) + 1001
        print 'new time is {}'.format(kTimeNew)
        keyframe(kf, e=True, index=idx, a=True, tc=kTimeNew)
        print keyframe(kf, q=True, index=idx, tc=True)

Note that there's also the scaleKeys command which also takes into account weighted curves, tangents, etc.

Also, to query keys of an object you can also use the maya.cmds.keys command to query to avoid the need for listConnections. Note that listConnections defaults to also listing out connections (outputs) and thus your code could also "shift keys" for those that are related to driven keyframes (Set Driven Keyframe).

Anyway, good to see these gists public! Keep on sharing.