Hi
The usual way is :
If you want cloth to blend with movement of body parts then yes you need to rig and animate cloth. For doing this you need to attach cloth to character rig and do “weight_paint” on cloth in your 3D Editor so that the cloth will follow the movement of the character rig.(Blender has an auto weight paint option which will lessen the painful work of weight painting )
there is an other ugly way 
you can cut and separate the cloth for each bone ex: for pants you need to cut it to 4 separate part (left_upper_leg, left_lower_leg , right_upper_leg, right_lower_leg)
https://wiki.blender.org/uploads/3/30/RST.21.png
the attach each part to it’s corresponding bone in JME using the AttachmentsNode this way each cloth part will follow the corresponding bone Transform.
Btw: for the realistic cloth simulation like in the video, there is two ways 1-real time simulation which is very CPU consuming 2- using baked soft body animation. for the second one the game engine should support vertex animation but jme does not support it but i am using a very simple trick to use baked soft body animation in jme . you may see this :
