I'm creating an HDA for a futuristic flying vehicle that will be animated primarily via a motion path. What makes it slightly more complicated is that I want to include the lights that make up the headlight array and a few extra pieces of geometry that will drive the mesh lights. Additionally, I want my follow path constraint intact so that I can easily point it to a curve.

In my scene I will ideally have several of these assets. What is the best way to allow me to bring in this car HDA, continue to update it's geometry, lookdev and so on, and be able to constrain each one to its own unique curve?

As of now the curve in which it attaches to is embedded in the HDA as a placeholder but I imagine I will have to promote a parameter at the object level that will point to this unique curve.

I've attached an image of how the HDA is currently constructed internally.

The only parameters that have been promoted are the ‘position’ and ‘roll’ attributes on the follow path constraint that lives in the constraint network of my car object.

not sure you are asking, as it sounds like you know what you are doing

you have a HDA of your car, promoted parameters for path, controls and whatever you need to vary per instance
then you duplicate the asset several times point to different curves and vary or animate the parameters
that all that is to it
if you want to update your asset, you unlock any of the cars, modify and save the new definition
or copy an asset as a new version if you want to version up, the usual HDA workflows

Got it. Thank you for the affirmation.

I guess what I’ve been unclear on, having never used multiple instances of the same HDA, is whether saving a new version based on one of the duplicates would somehow interfere with the unique object level tweaks I may have done on all the other variants. Seems like only the changes within the “subnet” would propagate but any unique value tweaks to the parameters promoted on the outside would remain independent.