[vtkusers] Volume Rendering

[Leila Baghdadi]

with respect to #2
I am pretty sure that the VTK book specifies that when you perfrom 
rotation you must go

rotationY
rotationX
rotationZ

and even there are pages showing you an example of how the results change 
if you go rotation ->X -> Y -> Z.

Please check the book

Hope this helps

Leila

On Mon, 2 Dec 2002, Florian Schmidt wrote:

> Hi.
> 
> 1. I am using a vtkopenGLTextureMapper2D to visualize a Volume of
> mri-data. I have, before that, tried the vtkVolumeRayCastMapper. While
> the Raycastmapper gives O.K. Results (talking bout rendering speed), i
> expectd like at least 20 fps from the GL-Mapper. My Data has Dimensions
> 256*128*64. I have working binary only drivers from NVidia installed. ut
> runs at 120fps ;). Well, when rotating the Volume with the openGL mapper
> i get about 3fps. Which is little..
> 
> Any Hints?
> 
> 2. Of course, we also Display Sices of the Volume. To extract the
> Slices, i use a vtkImageResliceObject, which works like a charm (Well,
> it took a while, until i found out, that the best way to select the
> intersecton point of the slices is to use
> vtkImageChageInformation::SetOriginTranslation() after using
> CenterImageOn()). I set up an own Imagereslice Object for each of the
> three SliceViewWIndows i open up. The only problem i got is, that when i
> specify (for the View with the X-Axes as Normal)
> 
> Transform->RotateX(0);
> Transform->RotateY(90);
> Transform->RotateZ(0);
> 
> with Transform being the Reslice-Transformation, i get a picture which
> has seemingly the spacing in one direction doubled. The outcoming
> picture should have the dimension 128x64, but it gets displayed as
> 128x128 with the pixels in y-dir doubled. If i do _not_ turn on
> AutoCrop, then the output is right, but, of course, has big black
> frames. It works fir the other two views, which have:
> 
> Transform->RotateX(0);
> Transform->RotateY(0);
> Transform->RotateZ(0);
> 
> 
> and
> 
> Transform->RotateX(90);
> Transform->RotateY(0);
> Transform->RotateZ(0);
> 
> Do i seriously misunderstand something. Do you need a peek at my Code?
> 
> T.I.A. Florian Schmidt
>