Reconstruct the lower body 8 (Patreon)

I finally prepared all the mask patterns for the lower body. However, when I checked the output, some of the frames were not masked properly. After several hours of agonizing... then I remembered that sometimes cropped images aren't masked by a bug in Flash. Then, I opened a waterway as shown in the figure.

 It's now displayed correctly. Huhh...

 Now for the final finish. It requires to apply the corresponding mask in real time from these patterns according to the state of the pants and the angle of the legs. Especially during high-speed piston motion, processing is performed every frame (1/24sec), so if the synchronization is slightly off...

This is what happens.

Set the function to select the appropriate mask just by calling it. I confirmed that it works without any problems. Now, after fixing a few more bugs, the lower body reconstruction will finally be completed.