OOOOPS! your right and disappointed me
but whats the benefit of this?
we can always select keyframes and move them. exactly the same behavior.
fcurve editors in 3D apps is a place for continues setting, editing and deletion of keyframes, not a place for holding a bunch of them intact in the process of animating. if we do not need to modify them, so animating phase has been finished and we will have no activity there. if animator would want to craft some animations after some pre-built animations (which would not them been altered again) then 3D apps' non linear tool game begins. a combination of non linear (a clip in maya trax editor) and linear animation (a fcurve in maya graph editor), which is possible in houdini too.
if the matter is shifting a bunch of keyframes, and simultaneously holding other keyframes untouched, something like “repel” tool is more logical or in a more advanced version using something like what maya calls “retimer”.
retmers can hold a bunch of keyframes grouped together in a spot ( a retimer can benefits from multiple vertical lines, assume space between each pair of them as one “spot” ) and while moving or even scaling the spot by moving its vertical lines, we affect the spot's included keyframes, and keyframes out of spot range fit themselves accordingly so that there will be no keyframes cluttering, among inside and outside of that spot.
by repositioning H groups we easily destroying group margin fcurves segments. so movement will be so limited. we can resemble this limited movement, simply by selecting keys and repositioning them.
i think H group's graphical representation is a good candidate to be something like maya retimer. more benefits.
moving retimer's each spoit vertical lines pair together, can hold included keyframes movement consistent related to each other( same as H group behavior )and at the same time spot repels surrounding keyframes, without destroying their segments. even they can perform time scaling over included keyframes by moving one of those two vertical lines of the spot, at the same time retimer respects repelling of excluded keyframes again. a great benefit is that by placing multiple vertical lines for retimers we can manage these behavior in multiple spots.
if houdini wants to save its keyframes group functionality as an extra benefit in the animation editor, it would be better to replace it with retimer.
this can be a nice RFE, specially very handy in character works:
as an additional bonus and so that houdini retimer be able to do defeat maya one, add the possibility of changing value of the keyframes in the spot, by implementing two point on each vertical line, capable to move separately along the line.
these four points of the spot, form a bounding rectangle around included keyframes that can be deformed by changing those points positions vertically over their owner vertical line and consequently can deform spot's included keyframes value. to be more handy add a soft falloff radius, so dense animation curves edit (like baked animation fcurves) be easier.
this will be more than a retimer. i think then SESI should name it something else. may be: tuner = time tuning + value tuning.
add a limited version of this tool to the timeline (without value tuners). character animators have many works to do there. i insist on this one, because due to pruning the need of spline drawing of the animation editor, it gives us some good performance gains.
SESI even can add a lattice deformer to the animation editor for easy editing of dense fcurves that maya has too, and add that extra falloff effect around the lines of the lattice which maya hasn't.
personally i never used this one, cause it brings up the same difficulty that moving H group cause in wide range movements.
