How to export simple vertex animation from Max?

So, I have the most basic vertex animation for a gauge: each keyframe moves 2
vertices in a single axis. Just an Edit Poly without skin/bones or other
modifiers. The animation does not get exported in the gltf. What am I missing?

I don’t think you can do vertex animation in the sim… (I would love LOVE to
be wrong on this…)

There are vertex animations in many of the default aircraft. For example those
with a control stick like the Pipistrel Virus have a piece of leather at the
base of the stick with vertex animation deforming it.

isn’t it skinning? all my material/vertex/UV animation experiments failed (did
them almost year ago), will be interesting if these may work somehow

Skinning is, as I understand, using bones…

You must use a Skin modifier, add some bones and assign their influence to
vertexes, then animate the bones with keyframing. This is the only way to do
vertex animation since FSX.

My understanding was that skinning/bones are just a tool for describing how to
animate vertices, thus my assumption being that if that works, then simple
vertex animation should also work. But looks like I’m wrong there, so I will
attempt to achieve the same result with Skin.

Hello. There is no support for morph targets at the moment. When in doubt,
check that page of the doc:
Regards, Sylvain