Like many I want to extend a roof over a porch without columns.
I got an idea from a Japanese r
There was a ridge which started in mid-roof and extend forward and down.
It occurred to me that this ridge the top plates and the rafters actually formed a triangular truss which could be extended further then a cantilever.
I made a sketch but do not see where to the attach it

You can buy cantilevered roof trusses. If you are going to get a permit, they will give you a lot of grief over a DIY roof system. Lots of engineering needed and unless you go all the way back to the main ridge, you will be limited by how much you can cantilever. Snow load, wind uplift, wall load etc, etc.

How far out do you want to go?