Quote - i remember i saw a production that can morph thigh or leg when people wear a stocking

You probably saw a product that included such morphs. But, there would not be any way to easily morph a figure whenever it was wearing any sort of stocking. Those morphs have to be done by hand. (Though, I bet someone could create a complex python script that would do it.)

The easist way to do this, yourself, would be to use magnets to deform the thighs or legs the way you wanted to. That way, you could morph the legs when needed, for any length of hose.

As for the product you're looking for, I remember seeing it as well. So, it must have been within the past couple of months. Just keep searching for "stockings" or "panty hose" and you should eventually find it.