This picture is not on the storyboard, I added it to connect the story.

I encountered some problems when doing this action. First of all, when I chose the controller of my hand, I chose the controller of the left hand, and the controller of the right hand would select together, so I asked Lucy.

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Lucy asked me if I opened the symmetry, I said no, and then she asked me to look at the controller in the outliner.

Here, I found that the left-hand controller is inside the right-hand controller, and I can only drag him out from the inside. So this problem is solved.

Also, I originally made an animation of a ball, but I didn’t put it on when I thought it was unnecessary. When making the ball picking animation, an error occurred when the first ball established the parent relationship. Yanh suggested that I hide and Create a new one.

I want to thank yanh and lucy for your help here.