if you send it to Mixamo then you have more options for animation but the download will be fbx file which is what most animation software i.e, Blender, Iclone and Maya like to use... these can all then export as a obj files but pure Adobe software is very limited for 3d options so...
Try to think about it another way, if we have a sinusoid (i.e. plane wave) in 2d, this means it varies in one direction, and does not vary in the perpendicular direction. But, to have a harmonic, we must have the function going to zero at the edges of our boundary. But since ...