  Human motion is a key function to communicate information. In the
application, short-form mobile video is so popular all over the world such as
Tik Tok. The users would like to add more VFX so as to pursue creativity and
personlity. Many special effects are added on the short video platform. These
gives the users more possibility to show off these personality. The common and
traditional way is to create the template of VFX. However, in order to
synthesis the perfect, the users have to tedious attempt to grasp the timing
and rhythm of new templates. It is not easy-to-use especially for the mobile
app. This paper aims to change the VFX synthesis by motion driven instead of
the traditional template matching. We propose the AI method to improve this VFX
synthesis. In detail, in order to add the special effect on the human body. The
skeleton extraction is essential in this system. We also propose a novel form
of LSTM to find out the user's intention by action recognition. The experiment
shows that our system enables to generate VFX for short video more easier and
efficient.
