this is probably a stooopid question but i will ask anyway

i have an animation in swift 3d that contains 3 or 4 objects.... i need one of the objects to disapear for certain length of time and then reappear. In flash i would jus insert a blank keyframe and then l8r jus reintroduce the symbol. it doesnt work like that in swift unforunately.

can anyone help?