The Vellum Pack SOP packs geometry and constraint inputs into a single
geometry. The output geometry will have a two packed primitives, one
for each of the inputs. The
vellum_type string attribute is created
to allow the geometry and constraints to be split up appropriately
Packing Vellum simulations into a single object makes it a lot easier to work with them, either using switches or merges they can be treated as a single wire. The Vellum Unpack SOP will undo this operation.
Add a name attribute to the packed primitives. Useful when merging multiple Vellum simulations together to track them when they unpack.