[Paraview] Smart volume rendering mode

[Sergi Mateo Bellido]

Hi,

I think that I found a bug in the smart volume rendering mode in 
Paraview 4.4.0 and 4.3.1 (I have not tried with older versions).

My input data is a XDMF file that indexes the data depending on the time 
step and two binary raw files for each time step that represent the 
values of two variables (a and b). For the sake of simplicity, this 
example  only has a time step.

If I open the xmdf and visualize the 'a' variable using the smart volume 
rendering mode, the visualization is wrong (you can see the results in 
wrong.png). However, the results are ok if I change the volume rendering 
mode to RayCast (good.png). They are also good If I filter the data 
associated to the 'b' variable, so It looks like the problem is that the 
rendering algorithm is not taking into account that I'm not visualizing 
all the variables. The GPU-based rendering has the same issue.

I tried also with Paraview 5.0.0-RC1. At the beginning I thought it was 
fixed (both visualizations were not so different) but then I realized 
that some data was not being printed when I was using the smart 
algorithm (wrong_5.0.0.png vs good_5.0.0.png).

You can download all the images from the following link:

https://www.dropbox.com/s/pyl06ur041hvtde/img.tar.gz?dl=0

Best regards,

Sergi