How do I route an arpeggio symbol to a playback technique?

Under “ornaments” in the playback technique window, “arpeggio up” and “arpeggio down” are available.
When I use the arpeggio up or down score markings, they change the MIDI notes to play an arpeggio accordingly.
Instead I want them to link to the “arpeggio up” and “arpeggio down” playback techniques so they can play samples rather.
I am not seeing how this is achieved.

Arpeggios currently don’t trigger any playback techniques. What kind of arpeggio does your sample library provide, and how are they triggered? Does your library expect a keyswitch and a chord, and then it will replace that with an arpeggiated version?

No, actually it is for percussion notation.

The common techniques on the mark tree and bell tree are notated with arpeggio markings. In this case, each is a sample of the up or down.

Sometimes they are notated with gliss markings, but I don’t think Dorico allows replacement of those either. I could notate with “downbow” and “upbow” markings, but I would prefer not to stray that far.

No, gliss markings don’t create technique changes either for the same reason as arpeggios (in that they usually can’t be used in isolation because they may depend on the pitches being triggered at the same time). This is something that we could consider for the future if it has an acknowledged meaning for percussion.

The utility of the addition would be contingent on how often sample libraries use one sample to represent the sweep.
If they sample individual notes, then presumably the arp and glissando playbacks could represent that (maybe not well though), but so far I have not encountered individual note samplings for the mark tree or bell tree.

Some examples-

Mark tree and bell tree from “How to Write for Percussion: A Comprehensive Guide to Percussion Composition”, 2nd edition:

Bell tree arpeggios- Samuel Adler, “The Study of Orchestration” 2nd edition
Mark tree glissando- John Williams, “Hedwig’s Theme” from “Harry Potter and the Sorcerer’s Stone Suite”

Just out of curiosity, how would your sample library control the speed/tempo of the “gliss” up or down?
Are you thinking of a specific sound library?

The library I am mapping at the moment is Cineperc. They use a few samples going up, and a few going down, then a few others like both directions or all over. The ones going up and down come in a few different lengths, so I have used a technique marking to distinguish long from short. I would prefer to use a length condition to trigger these, but that is only available in the expression map (not the percussion map). More to your question: the speed/length is only crude in a method like this. To be more exact a library would have to sample many more version to fit lengths, or provide a time stretch algorithm linked to a CC which you could tune to your liking. There is the third option of sampling every note on the mark tree and bell tree and you could piece together glisses to be very tight, but you may lose some of character of the mark tree given that the chimes hit into one another in Newton’s pendulum fashion when struck for normal playing.