[Paraview] multiblock and volume render

[Jean Favre]

>>On Mon, Jun 22, 2009 at 4:51 PM, Bam Ting <bampingting at gmail.com>
>>wrote:
>>
>>>I wrote a parallel reader using multiblock dataset. How do I do a
>>>volume
>>>rendering?

It turns out that I had to program my own filter last week, to
re-assemble multiple grids (each of them vtkUniformGrid), into one big
vtkImageData, to enable volume rendering. What I find interesting is
that you say you wrote your own parallel reader. Instead of building a
multi-block, could you not directly insert the data at the right
sub-extents of a *single* vtkImageData?

The filter I wrote did nothing more than find the global extents of each
grid, allocating a big vtkImageData, and stuffing the sub-arrays in the
right place. Sounds backwards and against what I suggest you should do
yourself. My problem is that I had to deal with AMR data in memory, with
multiple grids per level. That's also why I am not offering my filter
which relies on the AMR internal structure to find the sub-extents.
Would be useless to you.

By the way, I might be dumb, but I was never able to use the method
vtkImageData::CopyAndCastFrom() which I guess one should use. I wrote my
own loops over the I,J,K indices to make my filter work.

just 2 more cents


--
Jean
Swiss National Supercomputing Centre