[vtkusers] Volume Rendering

[Florian Schmidt]

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
-- 
mista.tapas at gmx.net
http://mistatapas.ath.cx
http://www.arted.biz/mista.tapas