Skin recognition or area selection

The skin on people is a very difficult matter to work on, due to people having wrinkles, scars birthmarks etc. Skin can also stretch and fold, and since the muscles beneath it can change in size (pulled or stretched), there are a lot of variables to consider.

Skin very often gets impossible to correct, when people move around differently like when You dance.

Auto recognise skin, maybe leaving out the face, or able to select the area with skin. That area can then be focused on by skin model, or left out. A more concentrated menu for that could be made if there is only “skin” to calculate so to say.

How do You make the model stay on the selected skin area if the person is moving around? Will it work with anker points?