MantisBT - VTKEdge

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Date Submitted

Last Update

0008549

VTKEdge

public

2009-02-17 03:35

2010-08-24 11:27

Reporter

Gianluca

Assigned To

François Bertel

Priority

normal

Severity

major

Reproducibility

always

Status

resolved

Resolution

fixed

Platform

OS Version

Summary

0008549: Volume rendering deformation

Description

When I use the vtkKWEVolumeMapper to render a (16 bit) volume in a window, I notice a strange "deformation" in the volume when I look from some point of view (usually at the corners). Look at this recorded video:

http://it.youtube.com/watch?v=C_GA6UHbUGo [^]

I use a perspective camera (the problem is always present, but it's by far more noticeable when I look at the volume closely). I notice that when I use a parallel projection camera the problem disappear. If I use software raycasting the problem disappear too. So, seems that it's a problem related to the GPU implementation of the ray-casting algorithm (class vtkKWEOpenGLGPUVolumeRayCastMapper) when a perspective camera is used.
I suspect that the problem could be related to the determination of the rays entry/exit point.

Steps To Reproduce

Additional Information

Here some info about the volume I used in the video:

ImageSize = (512, 512)
Number of Slice = 461
PixelSpacing = (0.71875, 0.71875)
SliceDistance = 1.5
BitDepth = 16
URL of dataset: http://pubimage.hcuge.ch:8080/DATA/MACOESSIX.zip [^] (130 Mb, folder: CT1 abdomen\AVEC I.V. - 5305).

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System configuration:

- Windows XP SP3;
- Visual Studio 2005 SP1;
- CPU: QuadCore Intel Core 2 Extreme QX9770 (3,4 Ghz) - FSB 1600 Mhz;
- GPU: 2 x nVidia Geforce GTX 280 (2 x 1GB) (connected in SLI);
- RAM: 4 GB DDR3 (1333 Mhz);
- MB: Asus Striker II Extreme (nVidia nForce 790i Ultra SLI);