hello
I cannot recall how to animate visiblity of an object, besides that
it had to be done with layers.
I have an group of objects that I hope to animate visibilty false 0-99 frames
and visibity true from frame 100 on.
Bullet hitting an coffeecup what is what I am making.
You can right click(or hover and press I) to insert a keyframe on the visibility(camera or eyeball) in the outliner. I don’t know how to add keyframes on a lot of objects(brokem pieces) at one time. 
hello SkpFX I did an solution with “old school”, two scenes,
visible breaking parts and other scene with intact coffeecup, but otherwise
the scene is same. Thank you though, I am quite sure that instruction will
be handy in future :), thanks.
You need to move an object to another layer and use exclude option in render layers tab. Hover and press I.
This turtorial can be helpfull:
Alternatively you can toggle on or off and key frame the “exclude” render layers by putting your group on a separate layer.
What I would do in this case is to create, say, two “Scenes” within your blend file, both derived from a parent Scene, and with different visiblity-settings, output-file destinations, and frame numbers. (Yes, you can toggle the visibility of objects in a variety of ways.)
Then, I would render the first version (group is visible …) for frame-numbers 0…120. And, in a separate set (of MultiLayer OpenEXR) frame files in a different directory …) frame-numbers 80-on.
Uh huh, the regions overlap, and that’s on purpose. Next, I would edit the sequences together in VSE or an equivalent video editor. The probability is quite high that I will want to “tweak” something … that “frame #99” is not the transition-point that I actually want to use. (And you’re not really going to know that until you can look at the whole show of which this tiny sequence is a tiny part.) By rendering some overlap, you have a bit of wiggling room.
If possible, I would render these as OpenGL Preview renders first … until I had finished(!) the final-cut edit and thereby now knew the correct sequences of frames that needed to be “final rendered.” One by one, these “finals” are swapped-in place of their preview stand-ins, until the show is done.
With OpenGL, you can afford to be quite wasteful of “film” because you can produce the stuff in nearly real time, and yet it corresponds exactly with the “finals” of the same thing.
Because rendering a CG show is still so damned expensive, you really want to “edit, then shoot.”