Multiblock datasets do not have a single set of points but rather a set of points for each block. You may either
- change your script to detect multiblocks and iterate over each block, transforming points for each dataset that inherits vtkPointSet or
- use the calculator filter with the “Coordinate Results” checkbox selected and a formula like
xCoord*sin(yCoord)*cos(zCoord)*iHat + ...; the calculator filter automatically iterates over blocks for you.
The latter is simpler unless you need to perform additional processing.