Ask HN: What software is China using to physically develop all these products?

I am looking out my window, I see a gazebo that took me a while to construct.

It has a number of fabric panels, attached to metal octo-arranged posts... a chuted chimney abatement...

How are chinese people designing such products?

Are they stolen STLs designs? What?

Also, and the core of this question: How do you develop skills to design such weird attrapments.

You certainly did NOT go to school to design such...

So. How are these built/designed?