So I have a digital asset that wraps a ROP node and promotes a multi-parm block from the ROP node to its top-level interface. The problem is that normally when a user changes the value of one of the menu parms on the native ROP node it triggers code (internal to the native ROP node, of course) that puts a value in an adjacent parm. But this does not happen when the user does the same thing to the promoted menu parm of that multi-parm block.

The specific case is our wrapped Redshift ROP. The AOV multi-parm block has a parm called RS_aovID_# and when you select which AOV you want (diffuse, specular, etc.) it auto-fills the adjacent RS_aovSuffix_# parm with a corresponding name string. However, this does not happen when the user selects the AOV type from the promoted menu on our containing digital asset. The adjacent name parm remains unchanged.

How do I get our wrapped OTL to trigger the native callback on the native ROP it is wrapping?

Thanks!

Anyone? Beuller?

Is this a Houdini bug? Or a case of “Houdini can't do that”?

I'm pretty sure you can't do that. Once a node is in a locked HDA, it's off limits–read only. Callbacks would have to be handled by the outer node.

I'm a firm proponent of never wrapping ROP nodes. They're always moving targets and implement too many callback/button features to survive the process without an inordinate amount of work.