[vtkusers] VTK, Python, MacOS X, Cocoa, Offscreen rendering?

[Bridgman, William T.]

Hello,

I've seen a number of notes on discussion boards suggesting that  
recent CVS checkouts of VTK will do offscreen rendering in the Mac OS  
Cocoa environment.

I'm trying to batch export RIB files on an XGrid cluster (Hundreds of  
files that take 5-15 minutes to process).

I've got vtkPython running with Cocoa but haven't found the sequence  
of commands that completely disables the window generation.  My  
simple-minded first guesses of

             renWin=vtk.vtkCocoaRenderWindow()
             renWin.OffScreenRenderingOn()

before installing actors, die with:

kCGErrorRangeCheck : Window Server communications from outside of  
session allowed for root and console user only
INIT_Processeses(), could not establish the default connection to the  
WindowServer.Abort

when run on the headless machines.  It runs fine without off-screen  
rendering on a console.  I suspect I'm missing something in the  
initialization sequence but am not that familiar with Cocoa.

Platform: MacOS X 10.4.11, G5 PPC

Suggestions?

Thanks,
Tom

**** Please Update my e-mail address to my *NEW* OneNASA address  
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Dr. William T."Tom" Bridgman               Scientific Visualization  
Studio
Global Science & Technology, Inc.          NASA/Goddard Space Flight  
Center
Email: William.T.Bridgman at nasa.gov         Code 610.3
Phone: 301-286-1346                        Greenbelt, MD 20771
FAX:   301-286-1634                        http://svs.gsfc.nasa.gov/