Is there any python or javascript library that can help in converting 3dm to skp file?
It requires local rhino setup. Can it be made to work from external environment like AWS lambda?
Not lambda specifically. But AWS, yes.
Suppose i have rhino doc object. Is it possible to get other file formats like obj, skp in a simpler way ?
Can i do it locally in browser or in lambda?
Running outside rhino in a browser you can try Rhino3dm.js. this will read rhino objects.
It really depends how much geometry processing needs to be done.
The Rhino3dm library only deals with rhino objects. It does not include libraries for other formats.
With Python you could call rhino on a local machine headless. Running it as Rhino.inside or a local version of compute. It requires a rhino license.
I am already running rhino.compute in aws and using appserver to display the geometry.
This provides a simple way to get .3dm from rhino doc. What i want to know is the algorithm or processing steps to get .obj or .skp files from rhino doc?
The code driven file.io guide above gives the trucks in rhino.
But there is also this long thread on compute and file io: Exports and imports using Rhino Compute