[Paraview] Lock Data Range for multiple attributes

[postgurke at web.de]

Hello All

Sorry to bother you again... I seem to miss something wanting to fix color scale
ranges for objects with multiple attributes. 
For example: I have a vtk-Plane with associated velocity and density values that
I can choose for coloring. When I imported the object, I set
LUT.RescaleTransferFunction(min, max) and LUT.LockDataRange = 1 for both
attributes (with different min,max, of course). In the GUI everything looks fine
at first, but when I switch the coloring from one attribute to another, ParaView
seems to ignore the checked "Lock Data Range" but switches to some Min/Max found
in the data. Maybe I misunderstand the functionality of "Lock Data Range"? Is
this the expected behaviour? If yes, what could I do to really fix the min,max
to my own specification? (I also tried to use a preset color scale with my
desired min,max, but this does not change the behaviour either.) 

Thanks for your support and any ideas on this,
Venke