[vtkusers] question about mapping textures to arbitrary shapes

[Wilson Chang]

Well, let me explain the big picture of what i'm trying to do, and maybe
that'll shed some light.

    Our data set is really a 3-D volume data set of ultrasound images.  What
the data set represents in 3-d physical space is if you took a globe, and
took a 60 degrees of latitude and 60 degrees of longitude wedge out of it,
much like a 4-sided pyramid with a rounded bottom.  The rounded bottom is
one of the points where I'm having trouble.

    Now like i mentioned before, ultrasound is strange in that it isnt
rectilinear.  Our data has 64 x 64 x 256 voxels, with the 64x64 representing
the sides of the pyramid, and the 256 representing the height of the pyramid
(from the tip of the pyramid to any voxel in the curved base).  What makes
this even more weird is that if you select a particular "height," say 150
for example, the 64x64 set of voxels at that height do not lie on a plane,
but rather on a curved surface.

    I would like to use some of the vtk slicers to visualized any arbitrary
plane through this data set.  And, if you followed me so far, i'm impressed
because my explaination probably wasnt that good.  Can anyone offer any
help?

Thanks for your help,

wilson



----- Original Message -----
From: "John Biddiscombe" <jbiddiscombe at skippingmouse.co.uk>
To: "Wilson" <wilson at cs.wisc.edu>; <vtkusers at public.kitware.com>
Sent: Tuesday, November 12, 2002 5:06 PM
Subject: Re: [vtkusers] question about mapping textures to arbitrary shapes


> Look at vtkTextureMapToPlane. If I read you right, you've got a 2D image
> that you want to stick on a pie shaped 2d polygon. Just project the image
> onto the polygon.
>
> Probably its not as simple as that...
>
> JB
>
> ----- Original Message -----
> From: "Wilson" <wilson at cs.wisc.edu>
> To: <vtkusers at public.kitware.com>
> Sent: Tuesday, November 12, 2002 9:54 PM
> Subject: [vtkusers] question about mapping textures to arbitrary shapes
>
>
> hi,
>     I am new to using VTK and I have a quesiton about how to map textures
to
> arbitrary shapes.  In my particular case, I am trying to visualize
> ultrasound data.  In this case, the data does not posess a rectilinear
> distribution, but rather it looks more like a pie wedge.
>     So, if my texture consists of a 2D array, how would I map it to a
wedge
> shape given I know where each texture/data point should map to in physical
> 2-D space?  I have taken a look at the vtkDataSetMapper, and I believe
that
> this is the right way to procede, but the details allude me.  Could anyone
> offer any insight on this matter?
>
> Wilson Chang
> MD/PhD Program
> University of Pittsburgh
> School of Medicine
> Dept of Bioengineering
>
>
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