[vtkusers] Error allocating memory :Volume rendering

[wassim_belhadj at topnet.tn]

Hi      

I launched two parallel reconstitions 3D (Volume rendering). 
when I tried to launch a third I got an error message 
"Unable to allocate 129499136 elements of size 2 bytes"

How to prevent this error in advance to to avoid potential problems ?

How to get an idea on the memory needed for the reconstitution (Volume
rendering). 

I'm using the vtkFixedPointVolumeRayCastMapper. 

Thank you in advance