This question is directed at the people who have optimized the scenes which are on UE4's marketplace or to anyone that knows the process.

I would love to know what tools&how have you optimized the models there. For example the Printer in the office scene.

It is pretty obvious to me that it has been done automatically with a tool that merges textures.

Did you guys use Simplygon for that ? Or maybe something else?

Would highly appreciate some help/advice as this is the most time consuming process in my work.