[Paraview] Visualization of strata in ParaView

[Steve Lamont]

Before starting, I should state that I'm a complete noob to ParaView, 
having only worked with it for a couple of weeks, so if this is a FAQ, I 
will be humbly abashed if pointed to somewhere rather obvious.

I have a dataset which is somewhat different than those which I believe 
are normally visualized with ParaView.  It is of geological strata and 
the samples are of discrete layers, rather than samples of some 
continuous function.  Furthermore, there are missing data or void regions.

I would like to display cross sections of these data showing the layers 
without color interpolation.  Is there a way to tell ParaView to display 
the colors in a step function rather than as a "continuous tone?"

Also, is there a way to tell ParaView to display the missing data as 
completely transparent -- in other words, setting the NaN color to 
having an opacity of zero?

Thanks for your attention and helpful RTFMs.

Regards.

							spl