[vtkusers] About Volume Rendering

[Tuhin Sinha]

"And any way to speed up the rendering process ( Like graphics
cards…etc..)"

Yes... there are two ways to speed up the rendering process.  Volume
texture map using 3D texture coordinates and do what is done in
vtkVolumeTextureMapper2D on the graphics card.  For consumer level
cards, we have seen a remarkable speed up in rendering times using the
Radeon 9800XT and a noticeable speed up using a QuadroFX 1000 for
medical images volumes (i.e. MR and CT: 256x256x256).  This method of
volume rendering is a cheat that is capable of providing compelling
images, but is not capable of providing all of the rendering
possibilities that a true ray cast can.

The second method to speed up volume rendering would be to write the ray
cast operation as a fragment shader for a late generation graphics
processing unit that can handle shader programs.  We have not
implemented this (yet), but I can't see why this wouldn't be at least as
fast as the software implementation in VTK if not substantially faster.

We have a class written for our lab that provides 3D volume texture
mapping using the OpenGL extensions in VTK.  I want to submit this to
VTK, but I have a dissertation to get done by the end of the month... so
progress on that front will be stunted until November.  The second thing
I am worried about w.r.t. to submitting the class is VTK's stance on the
use of more recent OpenGL specs (i.e. 1.4, 1.5 or 2.0).  It is my
understanding that VTK uses OpenGL v1.1... is this a must?

HTH,

Tuhin 

On Thu, 2004-09-30 at 03:04, kalyan.pushpala at wipro.com wrote:
> Hai All,
> 
>  
> 
> Iam using vtkRayCastMapper for volume Rendering.
> 
> Everything is fine and working( Ofcourse slow )
> 
>  
> 
> While iam rotating the volume the image is gets blurred while rotating
> and after I release the mouse button it taking time to come to its
> original state
> 
> Why that blurring is happening 
> 
>  
> 
> Any Method to get out of this problem 
> 
> And any way to speed up the rendering process ( Like graphics
> cards…etc..)
> 
>  
> 
> Thanking You in anticipation 
> 
> kalyan
> 
> 
> 
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