title: Vertex shader to create and animate geometry in QQuickItem
body: <p>I'm reading through the comments on this Qt bug report:</p>
  
  <p><a href="https://bugreports.qt-project.org/browse/QTBUG-32741" rel="nofollow">https://bugreports.qt-project.org/browse/QTBUG-32741</a></p>
  
  <p>That bug report suggests using a vertex shader with the <code>QSGGeometry</code> and animating in C++. I know the QML side supports shaders, but how do you access a shader from a <code>QSGGeometry</code> material that is handled via a C++ subclass of <code>QQuickItem</code> (as I interpret the bug report to suggest)? The vertex shaders accessed within QML are generally for deforming existing geometry, not really for creating new geometry or animating geometry, from what I can tell.</p>
  
  <p>Or is the report suggesting to bypass QML completely for this task?</p>
  
  <p>It would be pretty cool to pass data to a vertex shader for raw drawing and have the GL viewport be the Quick Item, but I don't think the QML shaders are designed for this.</p>