Nahuel Belich takes a look the basics as well as advanced use cases of the mirror modifier.
Did you use the mirror modifier, did you think that only works to mirror or copy geometry?
In this tutorial we are going to see how to use the different s option of this modifier to get the best use of it.
The first part are the basics of the modifier but the second part its for intermediate or advanced users, for the second part of this video, knowledge of uvs, rigging and vertex groups its recommended
