get/set component orientation for move/rotate/scale manip in custom shape

[benjamin ghys]

Hello!

I'm currently working on a custom C++ shape in Maya that inherits from MPxSurfaceShape.

My goal is to align the transformation gizmo (move/rotate/scale) with the orientation of the individual components of my shape.

Current Behavior: The transformation gizmo aligns with the orientation of the object, not the individual component(s).
Desired Behavior: I want the gizmo to align based on the orientation of the components I'm transforming.

There doesn't seem to be any function I can override for this specifically.

I tried multiple things:

I have overridden vertexOffsetDirection and works when transforming along the normal.

Sadly not for components.

I check the ApiMeshShape example but it also doesn't align the gizmo to the component like the basic mesh type does in Maya.

I checked MPxGeometryIterator and set hasNomals to true, but there is no method for returning normals?

I added a MPxTransform class but also no help from there as it is only plugs.

I checked the rockingChair example too but couldn't find anything.

I wonder if it is actually possible.

Maybe someone here has more experience with custom shapes?

Many thanks

Benjamin