Thanks Evgeny! I will track down your references and see how I go with this

Hi all,
I am a newbie and researching how best to go about creating an application that will allow users to construct a steel building framework by assembling 'modules' which are prisms with many flat faces based on an octahedral form. These prisms would be assembled on top and beside each other via connecting at the flat faces of adjoining prisms, a little like you assemble Lego building blocks but with more options for connection.

An important functional requirement would be for the blocks to 'snap' to each other when the relevant faces got in close proximity. I am presuming that I would need to use constraints to achieve this and wonderd if the current set of constraints in BFW can do this? If not, what is my best course of action?

Appreciate any guidance you might be able to give!