How to use the new associativeId parameter in BRep* definitions

[JesusFreke]

I was playing around with the new BRep*Definition functionality, and was trying to figure out a way to tie a particular BRepEdgeDefinition to it's corresponding BRepEdge in the created body. I see that there's an "associativeId" that sounds perfect for this... but I don't see any way to access/find/use the associativeId in the created body.

I thought maybe the id was used as the new BRepEdge's tempId, but they don't seem to match.

Is there any way to use the associativeId to link the BRep definition and corresponding created BRep objects?

(I love this new functionality, btw! I'm already finding it useful!)

[KrisKaplan · Accepted solution]

The purpose of the associativeId is to provide an input value into the tagging mechanism that is used for downstream associativity. So if you use one of these transient BRep bodies in a BaseFeature, a downstream dependency can be made to a specific face on that body (e.g. create a sketch on that face). If you later update the BaseFeature's body with a new one that used a consistent associativeId scheme, then the 'same' face will be referenced by the downstream dependency.

Internally, we do use this associativeId to map from the definition to the resulting topology for this tagging. But we don't have an API to expose this mapping after the create. This could be an enhancement request to the BRepBodyDefinition API (it would be another output of the 'create' method, or cached for later use like the 'outcomeInfo').

Kris

[JesusFreke]

Ah, thanks for the info! That makes sense.

I think it could definitely be useful if the tag info was somehow made available on the created BRep objects.

[kandennti]

Hi @JesusFreke .

I don't understand the purpose, but can't I use entityToken and findEntityByToken?

https://help.autodesk.com/view/fusion360/ENU/?guid=GUID-D9458206-A7FA-4371-94BA-636FE58F225C 

https://help.autodesk.com/view/fusion360/ENU/?guid=GUID-63F88589-9865-4866-A2F9-2FEEFED725D6 

[KrisKaplan]

The entity token allows you to create a token from an entity that can be bound back to that entity at a different time. What he was looking for was a way to map from a BRepFaceDefinition (or edge) to the resulting BRepFace after creation of a transient BRep. Transient BReps or their definitions do not support entity tokens (those are only usable for persistent entities).

Kris

[kandennti]

Thanks @KrisKaplan .

I interpreted that there is no way to access the associativeID from the Return Value (BRepBody) of createBody.