[vtkusers] Volume rendering algorithms?

[Cotin, Stephane M]

Hi Lisa,

Could you be more specific about the Volume Rendering algorithms implemented
in VTK in terms of accuracy and speed?
How accurate and fast (on a scale from 1 to 100) would you rate these
algorithms by comparison to the "best" algorithms / implementations you are
aware of (with no hardware acceleration).
How fast is the texture mapping approach (with hardware acceleration)
compared to the ray casting approach?
What would you suggest we do to speed up the ray casting algorithm (if it's
possible)?

Thanks a lot,

-Stephane 

	-----Original Message-----
	From:	Lisa Sobierajski Avila [SMTP:lisa.avila at kitware.com]
	Sent:	Thursday, June 15, 2000 2:52 PM
	To:	Jim Morash; vtkusers at public.kitware.com
	Subject:	Re: [vtkusers] Volume rendering algorithms?

	Hello Jim,

	These volume mappers are available:

	vtkVolumeRayCastMapper - a software ray casting approach. Slow, but
accurate.

	vtkVolumeTextureMapper2D - a 2D texture mapping approach. Can be
reasonably 
	fast if you have good 2D texture mapping support. Less accurate than
ray 
	casting, especially for low-depth frame buffers.

	vtkVolumeProMapper - if you happen to have a VolumePro volume
rendering 
	board by RTViz, then this mapper will make use of that hardware.
Very fast.

	If you want to add your own you would need to create a new subclass
of 
	vtkVolumeMapper. You can follow the ray casting API, render directly
into 
	the graphics context, or you can provide an image back to the
renderer. If 
	you are providing an image back, you are responsible for asking the 
	renderer for the current RGB and Z buffers and merging your results
in.


	Lisa


	At 01:49 PM 6/15/00, Jim Morash wrote:

	>Hi all,
	>I'm just getting started with VTK and I may be using it for a
medical
	>visualization application. Could anyone tell me what the included
	>options are for volume rendering algorithms, and give me some idea
of
	>how hard it would be to add them if I want to try something that's
not
	>included?
	>thanks,
	>--Jim Morash
	>
	>------------------------------------------------------------------
	>Loyalty to petrified opinions never yet broke a chain or freed a
	>human soul in this world--and never will. --Mark Twain
	>------------------------------------------------------------------
	>jmorash at mit.edu                     http://web.mit.edu/jmorash/www
	>
	>_______________________________________________
	>This is the private VTK discussion list.
	>Please keep messages on-topic. Check the FAQ at: 
	><http://public.kitware.com/cgi-bin/vtkfaq>
	>vtkusers mailing list
	>vtkusers at public.kitware.com
	>http://public.kitware.com/mailman/listinfo/vtkusers



	_______________________________________________
	This is the private VTK discussion list. 
	Please keep messages on-topic. Check the FAQ at:
<http://public.kitware.com/cgi-bin/vtkfaq>
	vtkusers mailing list
	vtkusers at public.kitware.com
	http://public.kitware.com/mailman/listinfo/vtkusers