[vtkusers] get tcoords from pointId

[Cory Quammen]

Marco,

I don't know of a class method that lets you look up the color given a
texture coordinate. I think you'll have to compute the pixel
coordinate, which shouldn't be too hard.

- Cory

On Thu, Dec 18, 2014 at 4:09 PM, marco <piccima at gmail.com> wrote:
> Hello
> I was able to retrieve the tcoords for my Points.
> Now I'm trying to access the texture image to get the rgb value for that
> location.
> Is possible to use directly the tcoords to do that? or I have to compute the
> pixel coordinate with a transformation?
>
> Thank you for your help
>
> Marco
>
>
> On 12/18/2014 02:33 PM, Cory Quammen wrote:
>>
>> Hi Marco,
>>
>> Texture coordinates are stored in an array in a vtkDataSet's
>> vtkPointData object. Say you have a vtkPolyData with texture
>> coordinates. To access it, you would do something like
>>
>> vtkPointData* pd = polyData->GetPointData();
>> vtkDataArray* tcoords = pd->GetTCoords();
>>
>> // Let's assume the tcoords are in a vtkFloatArray
>> vtkFloatArray* floatTcoords = vtkFloatArray::SafeDownCast(tcoords);
>> if (floatTCoords)
>>    {
>>    float texCoord[3];
>>    floatTcoords->GetTupleValue(pointId, texCoord);
>>
>>    // do something with texCoord
>>    }
>>
>> I hope that helps,
>> Cory
>>
>> On Thu, Dec 18, 2014 at 1:58 PM, marco <piccima at gmail.com> wrote:
>>>
>>> Hello,
>>> maybe it has been deprecated but I cannot find a method like
>>> GetTcoords(pointId)!
>>> Is there something similar in the library?
>>>
>>> Thank you
>>>
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>>
>>
>



-- 
Cory Quammen
R&D Engineer
Kitware, Inc.