[vtkusers] Re: hardware stereo swapped LR images in raycast, but not 2D texture, in volume rendering

[Nicholas Schwarz]

Hi,

I am also experiencing reversed stereo pairs (i.e. the left eye is
displayed where the right eye should be, and the right eye is displayed
where the left eye should be) when using RayCasting in CrystalEyes mode. I
do not think it has anything to do with you're mayavi stuff because I'm
not using it. I do think the problem might be in vtkVolumeRayCastMapper.

I posted a message about this on 11 August 2003 here
http://public.kitware.com/pipermail/vtkusers/2003-August/019505.html, but
I still don't have a solution.

If you discover a fix please let me know.

-------------------------------------------------------------------------
Nicholas Schwarz
Electronic Visualization Laboratory           E-Mail: schwarz at evl.uic.edu
Department of Computer Science                Telephone: 312-996-3002
University of Illinois at Chicago             Facsimile: 312-413-7585
-------------------------------------------------------------------------

> Date: Tue, 19 Aug 2003 15:14:50 +0300
> From: "Dr. Daniel James White PhD" <dan at chalkie.org.uk>
> To: mayavi-users at lists.sourceforge.net, vtkusers at vtk.org
> Subject: [vtkusers] hardware stereo swapped LR images in raycast, but not 2D texture in volume rendering
> 
> Hi ,
> 
> I am experiencing a strange stereo problem using VTK with the mayavi=20
> frontend,
> concerning display of hardware stereo using a crystaleyes glasses system
> on a redhat linux 8.0 box with ATI radeon 7500, and the Xig.com Xserver=20=
> 
> for quad buffered stereo.
> 
> When I load in the IronProtein.vtk example file
> and use the new Mayavi module
> volume
> by Gerard Gorman (see mayavi list recently)
> 
> then turn on the
> SetStereoTypetoCrystalEyes
> and
> StereoRenderOn
> in the
> Configure vtkXOpenGLRenderWindow
> dialog box
> 
> Now when I rotate the data set , I think the faster=20
> vtkVolumeTextureMapper2D is used.
> In hardware stereo this looks correct (but it is fuzzy so a bit hard to=20=
> 
> tell)
> 
> however, when the rotation is finished the slower
> vtkVolumeRayCastMapper is used for a nice rendered image.
> When rendering is finished the left and right images are displayed=20
> incorrectly!
> What the dialog boxes think is the right image is actually the left=20
> image, and vice versa.
> 
> This behavior is also seen with a python script I cobbled together to=20
> display stacks of tiff images
> using ivtk from mayavi.
> 
> Is the problem a bug in the vtkVolumeTextureMapper2D or somewhere=20
> upstream?
> 
> Hardware stereo functions correctly in other software such as pymol and=20=
> 
> bodil.
> 
> Previously I have applied a little hack to mayavi to enable stereo=20
> viewing as suggested by
> Prabhu Ramachandran.
> 
> also SetStereoTypeToLeft gives the same incorrect/swapped double image=20=
> 
> as SetStereoTypetoCrystalEyes.
> but SetStereoTypeToRight only displays 1 image to both eyes.
> 
> When StereoRenderOn is turned off, or not turned on, same thing,
> only the right eye sees and image, and the screen is blank to the left=20=
> 
> eye, casing a flickering, or half intensity image.
> 
> I don't know if the hack to mayavi  has caused this problem?
> I don't think the flickering happened before I applied the hack.
> 
> any ideas VTK stereo folks?
> 
> cheers
> 
> Dan
> 
> 
> Dr. Daniel James White BSc. (Hons.) PhD
> Cell Biology
> Department of biological and environmental science
> PO Box  35
> University of Jyv=E4skyl=E4
> Jyv=E4skyl=E4 FIN 40014
> Finland
> +358 (0)14 260 4183 (work)
> +358 (0)414740463 (mob)
> 
> http://www.chalkie.org.uk
> dan at chalkie.org.uk
> white at cc.jyu.fi