[vtkusers] masking data

[Iyer Arvind Sundaram]

my domain is quite huge, and i wish to plot the glyph of the velocity vector.

 glyph at all points is useless and time consuming as well as unclear.

Non random masking causes non uniform arrangement of the masked points.

Random masking changes the points list every time it is called. I need to 
create a sequence of several glyph-frames to simulate a transient process.

Being so, what i exactly need is a random selection of masked points initially 
which do not change thereafter. is there a way to do that?

Can i create a random list of the points (un)masked and use the same list 
every time??