How to visualize an object like Cad Assistant does

Hi All,
I am developing a custom 3d viewer.
I would like display 3d shaded objects about like Cad-Assistant does ( see attached picture)
can someone show me how to achieve this?
Thanks

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Kirill Gavrilov's picture

It would be helpful to describe what you have been already done to figure out at which step you are looking for a help.