Errors in Coprocessing
This issue was created automatically from an original Mantis Issue. Further discussion may take place here.
I've included a "simulator" (cop.C) which follows the Coprocessing_example from the wiki. In each of 2 processes in an MPI run, it creates a partition of an 8x8x8 structured dataset (using vtkImageData), dividing along Z at 3. Each process then writes out its partition explicitly, and then hands it to the co-processor.
The co-processor ("vol.py") is produced using the plugin, and consists of an input that is passed directly to the Parallel Image Data Writer. I created this using an unpartitioned 8x8x8 vtkImageData object ("single.vti").
When I run the simulator, two sets of two vti files are created - one (part_{0,1}.vti) that the simulator wrote explicitly, and one (volume_0_{0,1}.vti) that is produced by the co-processor as partitions of volume_0.pvti. If you look at the extents of the explicitly written partitions, you see 0,7,0,7,0,3 and 0,7,0,7,3,7 - which I would expect. However, if you look at the extents in the co-processor produced .vti's you see 0,7,0,3,0,3 and 0,7,3,7,3,7, and the .pvti file can't be input to PV.
"cop8.C" is a similar "simulation" that divides the same 8x8x8 space along each axis at 3. "contour.py" is a co-processing script that runs a contour filter and produces a .pvtp file. If I load that and overlay it with the bounding boxes of the 8 .vti files that are explicitly written by cop8.C, I get whats seen in bad.png. If I run Contour on the 8 .vti's (at 13.5) I get good.png, which is what I'd expect. Note that at least some of the bad contour fragments are at least in the correct plane.