[vtkusers] How to import NASA SRTM DEM data into VTK

[Michael Jackson]

http://www.vtk.org/doc/release/5.2/html/a00665.html#b853fba8decf9550e4678fa4f4ca9ad0

Page 405 in the 4th edition of the "Visualization Toolkit" explains  
what the data extents are.

Basically they are the min/max (in x,y,z) of your data. For example if  
your data was 100x 50 x10 but the actual minimum value was 1000, 1000,  
1000 (x, y, z) then your data extents would be 1000, 1101, 1000, 1051,  
1000, 1011 (Xmin, Xmax, Ymin, Ymax, Zmin, Zmax).


_________________________________________________________
Mike Jackson                  mike.jackson at bluequartz.net
             www.bluequartz.net



On Oct 13, 2008, at 9:23 AM, Elvis Dowson wrote:

> Hi Mathieu,
>                        :-) I didn't understand the answer. :-)  The  
> data that is encoded in the STRM file is signed 16-bit integer.   
> What do the parameters for SetDataExtent mean?
>
> What value should I multiply sizeof(int) with?
>
> Thanks!
>
> Best regards,
>
> Elvis Dowson
>
>
> On Oct 13, 2008, at 5:18 PM, Mathieu Malaterre wrote:
>
>> On Mon, Oct 13, 2008 at 3:17 PM, Mathieu Malaterre
>> <mathieu.malaterre at gmail.com> wrote:
>>> On Mon, Oct 13, 2008 at 1:57 PM, Elvis Dowson  
>>> <elvis.dowson at mac.com> wrote:
>>>> The image data is 1201x1201 array using 16-bit signed integers,  
>>>> but it kept
>>>> crashing when I use SetDataExtent 0 1201 0 1201 0 0.
>>>
>>> => [1202,1202,1] dimensions
>>>
>>> what is the output of :
>>>
>>> $ ls -al  "/Users/elvis/Repository/Data/NASASRTM/version2/SRTM3/ 
>>> Eurasia/N25E070.hgt"
>>>
>>> answer:
>>> it should be 1201 * 1201 * 1
>>
>> ... * sizeof(ushort)
>>
>> :)
>>
>> -- 
>> Mathieu
>
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