I can not find a plug-in, that makes it possible to create an animated reflection. on the "floor" I have a sequence with a 3D cube and some text Is there a plug-in that can do the job I use AE 5CS
Video Copilot offers a free plugin that fakes reflections.
Zaxwerks offers a plugin that actually does reflections.
You can sort of fake it by placing a strong backlight and turning your layers into light transmission objects and telling the floor to accept shadows.
These aren't true mirror-style reflections but the effect can be very cool.
Szalam and bogiesan have already given you all that you need, but here's a search that pulls up several alternatives, including some tutorials by Andrew Kramer.
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