[vtkusers] how to read UNSTRUCTURED_GRID?

[이정규]

Sorry I've found that there's one more line with directive "DIMENSIONS"

# vtk DataFile Version 3.0
vtk output
ASCII
DATASET STRUCTURED_GRID
DIMENSIONS 20 30 40
POINTS 24000 float

.............

and obviously, 20*30*40 == 24,000. Given this, how should I arrange those
points to get the exact same result as paraview?

If I have to do it manually, maybe I should start working with smaller
model, but is there really no documentation on this?????(to Kitware : if
it's NDA please let me know)

On Mon, Mar 15, 2010 at 10:45 AM, 이정규 <glazex2 at naver.com> wrote:

> Hi David,
>
> Thank you for your reply and the suggestion, however the file I'm working
> on is so-called a legacy VTK file that does not have the newer XML
> structure. But from the wiki page that you suggested, I found more
> information.
>
> Structured Grid
>
> Regular topology and irregular geometry. That is, every point has a left,
> right, up, down, front, back neighbor. The points, however, do not lie on a
> grid! You must explicitly indicate the coordinates of each point.
>
> This data structure is common in finite difference analysis.
>
>
> This information gives me food for thought, but is not clear enough that
> which goes which.
>
> For example, if I have
>
> x1,y2,z3,x2,y2,z3,x3,y3,z3,x4,y4,z4,x5,y5,z5,x6,y6,z6,x7,y7,z7,x8,y8,z8
>
> I guess it would be something like
>
> (x1,y1,z1),(x2,y2,z2),(x3,y3,z3),(x4,y4,z4)
>
> for the first face.. but what about the next face?? If it have to share
> some points(maybe 2, if it have to) with the first face, what would it be
> like?
>
> Also, if it indeed share some points with its neighboring grids, how many
> grid should I expect from n points?
>
>
> Truly yours,
>
> --
>
> Jeonggyu Lee
>
> On Mon, Mar 15, 2010 at 10:22 AM, David Doria <daviddoria+vtk at gmail.com<daviddoria%2Bvtk at gmail.com>
> > wrote:
>
>> On Mon, Mar 15, 2010 at 11:19 AM, 이정규 <glazex2 at naver.com> wrote:
>>
>>> Hi all,
>>>
>>> I am trying to parse a .VTK file with UNSTRUCTURED_GRID but this just
>>> have data of points.
>>> I've looked for more information for this but all I found is
>>>
>>> The Visualization Toolkit supports five different dataset formats:
>>>> structured points, structured grid, rectilinear
>>>
>>> grid, unstructured grid, and polygonal data. Data with implicit topology
>>>> (structured data such as vtkImageData and
>>>
>>> vtkStructuredGrid) are ordered with x increasing fastest, then y, then z.
>>>> These formats are as follows.
>>>
>>>
>>> So I guess somehow I have to infer the topology from these points. I've
>>> tried Paraview and it renders it as a set of rectangles(I've tired to render
>>> surface with wireframes and so on)..
>>> I see some hint there that points are ordered with x-ascending order, but
>>> how the index is consists up is not mentioned in any documents.....
>>> Anybody done this before? or have more information for this?
>>>
>>> PS : If you are someone at Kitware, would you please, please direct me to
>>> the right information?????
>>>
>>> --
>>> Jeonggyu Lee
>>>
>>
>> Do you have an existing .vtk file that you need to read? If not, I would
>> suggest using the XML .vtu format - then you can use:
>>
>> http://www.vtk.org/Wiki/VTK/Examples/IO/ReadUnstructuredGrid
>>
>> Thanks,
>>
>> David
>>
>
>
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