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

[Michael Jackson]

Nope.

Your data arrays are 1201 elements in x and y which means the data  
extent in the X and Y directions are 1201 + 1 = 1202.

Since there is only 1 "slice" of the data then the z data extent is 1  
or (0,1);

I am assuming once you get the data into VTk you will probably run an  
"ElevationFilter" on it?


_________________________________________________________
Mike Jackson                  mike.jackson at bluequartz.net
BlueQuartz Software                    www.bluequartz.net
Principal Software Engineer                  Dayton, Ohio

On Oct 13, 2008, at 9:44 AM, Elvis Dowson wrote:

> Hi Mike,
>                  I'm just not sure about one thing. If the x, y  
> values are to hold pixel co-ordinates, what will it's value range be  
> for a [1201] [1201] array? Will in be x min =0  x max = 1201 y min =  
> 0 y max = 1201 ?
>
> The elevation data is stored in meters, and it's a signed integer,  
> so it's value can range from -32767 to 32767.
>
> So, will the correct set of parameters for my SetDataExtents be 0  
> 1201 0 1201 -32767 32767 ?
>
> Best regards,
>
> Elvis Dowson
>
>
> On Oct 13, 2008, at 5:32 PM, Michael Jackson wrote:
>
>> 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).
>>
>>