Unsolved Dynamic updates to a QVertexBuffer in Qt3D

[Marburg]

Like others, I am trying to show dynamic content in Qt3D. In my case, I have created a QGeometry for modelling a point cloud and I want to incrementally update / change that point cloud.

I have a slot within my QGeometry which is called when the underlying model changes. Within that callback I run vertexBuffer->setData( ... ), but the display doesn't update. Is there a signal that I'm not propagating?

This is with Qt 5.7 installed from binary on both Linux and OSX, running OpenGL 4.x on both.

See also:
https://forum.qt.io/topic/70378/updating-buffer-data-frame-by-frame