Is there some way to stretch a sprite in a NinePatch style for a Sprit3D?
Possible to make some 3D UI like this?
There is no NinePatchSprite or NinePatchSprite3D yet. There's NinePatchRect, but since it inherits from Control, it's intended to be used for GUI design… which is precisely what you want to be doing here :)
Take a look at the GUI in 3D demo.