[vtkusers] VS: ÄvtkusersÅ Performance of 2DMapping

[Hämäläinen Janne]

Thanks for you fast answer. I have to figure out what is the best way to do
things. It just feels a bit funny to show images in 3D if there is 2D mode
available. Thanks also for the last comment, I hadn't realized that you can
use stencils also in vtkImageBlend. 

Cheers, 

Janne

P.S. You were in time. JB answered my other question.


> ----------
> Lähettäjä: 	David Gobbi[SMTP:dgobbi at imaging.robarts.ca]
> Lähetetty: 	17. heinäkuuta 2003 16:49
> Vastaanottaja: 	Hämäläinen Janne
> Kopio: 	'vtkusersÉvtk.org'
> Aihe:  	Re: ÄvtkusersÅ Performance of 2DMapping
> 
> Hi Janne,
> 
> This depends on the OpenGL drivers and the graphics card.
> Some manufacturers' OpenGL drivers only use AGP for transferring
> textures and geometry, but not 2D images.  Some graphics cards
> don't provide an accelerated 2D image path at all.
> 
> So definitely use textures if you can, even for 2D viewing.
> The only difficulty with textures is the 2^N limitation.
> 
> Looks like JB beat me to the punch, but I'm sending this
> out anyway.
> 
>  - DG
> 
> P.S. Good to hear that someone is using vtkImageStencil!
> Note that vtkImageBlend can do everything vtkImageStencil
> can do, and then some.
> 
> 
> On Thu, 17 Jul 2003, Hämäläinen Janne wrote:
> 
> > Hi,
> >
> > I've used combination of vtkImageMapper and vtkActor2D to present 2D
> images.
> > Recently I tried presenting the same images using vtkImageActor, i.e.,
> in
> > effect putting them to 3D. I noticed that all the operations, e.g.,
> > windowing and leveling of the gray level and swapping regions between
> images
> > (as with vtkImageStencil) work much faster. In other words, the display
> > updating is much smoother. Is my observation correct, and is this in
> general
> > the case (or does it depend, e.g., on the used graphics card)? My first
> > hunch would be that the 3D mode uses hardware acceleration and in 2D the
> > processing would be done in software. Has anyone idea how things are
> > working, and is there any reason to use 2D mapping?
> >
> > Thanks,
> >
> > Janne
> >
> >
> >
> > --
> > Janne Hämäläinen
> > Research Assistant
> > Helsinki University Central Hospital
> > X-ray Department
> >
> > email   janne.hamalainen at hus.fi
> >
> >
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>