good point. I think I will change it to log if condition is true, which seems a more natural way – incidentally, that’s how it’s implemented, I just had it wrong in the docs – I’ll update it.
The vtkLogIff is indeed a unfortunate occurrence. The lower f was chosen to match printf, but by strict VTK style, -f should indeed be capitalized. Unless there’s objection I will change that accordingly as well.
fixes included here