[vtkusers] Performance of 2DMapping

[Hämäläinen Janne]

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