"Animate In" or fade in

Hi I am doing an animation of a barrel, where the objects appear or “fade in”. I tried to animate the alpha of the materials, but some objects share the same material, and they fade altogether instead of each one.

Anyone has an answer to this or there is a better way to achieve this?


I sorted out the alpha of the objects by adding new materials to the objects ex. bare_oak001,002… etc, but when are in alpha they overwrite the other objects, making strange artifacts… anyone knows the proper way to achieve this?