Module structure 

Where a file’s bodies are: the shape representations holding them, the units and uncertainty each is in, and — for an assembly — where its parts are placed, flattened into one placement per body.

A product’s shape is a representation of items — solids, sheets, placements — in a context that gives its units. Representations related without a transformation (a product’s shape and the B-rep representation holding its solid, say) share their coordinates. An assembly places the shape of each component in its own through a relationship with an ITEM_DEFINED_TRANSFORMATION, tied to the NEXT_ASSEMBLY_USAGE_OCCURRENCE saying which product is placed in which; a MAPPED_ITEM places one representation within another the same way. Every body is found by walking down from the products nothing places, composing placements on the way.

Structs

Item

A body to import: the solid or sheet #id, read in scope, and what it is called — its own name, or else the product it is the shape of.