Store Mesh in database
Are you considering using SQL Server to query data inside the mesh? For example, are you trying to pass in a list of points, and then have SQL Server figure out whether points in that area match up to any of the mesh data for existing rows inside the database?

If so, you're gonna have a bad time - that's not what SQL Server is designed for.

If, on the other hand, you're just using SQL Server as a key/value store ("give me the mesh data for this desk design") then you can use any data type you like, like JSON or XML or BINARY. You're correct, though, by saying that this rarely ends well. If you're looking for key/value storage, then use a key/value data store instead.