[vtkusers] vtkFloatArray::GetTuple Problem/Error

[de Boer Ingo]

Hi all,

I have a problem in
vtkFloatArray::GetTuple(const vtkIdType i, float * tuple)

Somehow/Sometime I get i < 0 (like -842150451). The call
comes from vtkPolygon::ComputeNormal, which comes from
vtkOpenGLDrawST3.

The solution I did was: 
  vtkIdType id = i;
  if (id < 0) id = 0;
  float *t = this->Array + this->NumberOfComponents*id;
instead of
  float *t = this->Array + this->NumberOfComponents*i;

This works and my object is shown as expected. But I was wondering
how this can happen ? The object that I show has texture, points and
polygons. The polygons are given and not calculated by VTK. This error
above happens only on certain objects, not with all my objects/files.

Any Hints ?

greets
  Ingo

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Dr.-Ing. Ingo H. de Boer

Polytec GmbH
Polytec-Platz 1-7, 76337 Waldbronn, Germany
phone: ++49 7243 604 106
fax  : ++49 7243 604 255