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IDProjectCategoryView StatusDate SubmittedLast Update
0002862VTK(No Category)public2006-02-08 16:052016-08-12 09:54
ReporterNick Gnedin 
Assigned ToWill Schroeder 
PrioritynormalSeveritymajorReproducibilityalways
StatusclosedResolutionmoved 
PlatformOSOS Version
Product Version 
Target VersionFixed in Version 
Summary0002862: Possible loss of precision
DescriptionI might have discovered a possible bug in VTK. The attached file gives a simple test where squares of decreasing size are placed in front of each other, so that smaller squares are in front of larger ones. Squares are sized by factors of 2, and there are 31 of them, so the smallest one has size of about 1e-9 of the largest one, and cannot be described by single precision coordinates. I use vtkPoints(VTK_DOUBLE) to insure that all coordinates are in double precision. Nevertheless, as you can see by running the test, the artifacts appear when the camera zooms to squares that are about 1e-7 of the largest ones, as if the coordinates are kept in floats despite being requested as doubles.

I am not 100% sure it is a bug in VTK, but I did try this test on two different video cards, one NVIDIA (under Linux) and another ATI (under Windows), to reduce a chance that the bug is in the OpenGL implementation.

The same behaviour appears under VTK 4.4.2 and 5.0.0.
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Attached Filescpp file icon Test.cpp [^] (2,710 bytes) 1969-12-31 19:00

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  Notes
(0036825)
Kitware Robot (administrator)
2016-08-12 09:54

Resolving issue as `moved`.

This issue tracker is no longer used. Further discussion of this issue may take place in the current VTK Issues page linked in the banner at the top of this page.

 Issue History
Date Modified Username Field Change
2011-06-16 13:11 Zack Galbreath Category => (No Category)
2016-08-12 09:54 Kitware Robot Note Added: 0036825
2016-08-12 09:54 Kitware Robot Status expired => closed
2016-08-12 09:54 Kitware Robot Resolution open => moved


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