render->GetZ(x,y) error

Dear People,
I use render->GetZ(x, y) to get the Z value of my mouse in screen, but it can’t work,
it will give an error in vtk window
vtkOpenGLState.cxx:203 WARN| Error in cache state for GL_READ_FRAMEBUFFER_BINDING

How to use GetZ to get the Z value?


Posting the code involved in the operation is a good start. :slightly_smiling_face: