| Re: Cropping of IDLgrVolume? [message #33826] |
Mon, 03 February 2003 01:17 |
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s[1]
Messages: 21
Registered: December 2002
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Junior Member |
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On Fri, 31 Jan 2003, Karl Schultz wrote:
>
> "Sebastian" <s@visita2.die.upm.es> wrote in message
> news:Pine.LNX.4.44.0301311717440.9316-100000@visita2.die.upm .es...
>> Hi all,
>>
>> does anybody know how to crop an IDLgrVolume?
>
> The CUTTING_PLANES property.
> As of 5.6, the CLIPPING_PLANES property.
>
>> What I would like to do is this:
>> Suppose your volume is a cube, then you can subdivide it into 8 equally
>> sized sub-cubes.
>> I would like to blend off one of these cubes.
>
> You can use the CUTTING_PLANES property to cut the volume so that only one
> of the eight sub-cubes are displayed.
> I don't think that you can restrict the extent of the planes to do selective
> cutting that might let you remove one sub-cube, leaving the seven others.
> Is this what you want?
That's exactly what I want. The only way to do this seem to store the
volume data, create a cut-off mask of the same size as the volume, and
create a temporary cut volume by multiplying the original volume with the
cut-off mask.
Not very elegant, but works (I was surprised how fast the multiplication
is).
BTW, what I wanted to render is something like this:
http://www.uke.uni-hamburg.de/institute/imdm/idv/forschung/v m/images/brainbloodsupplyareas.gif
>
>> And, more advanced, blend off the region of a small cube I position
>> somewhere in my original volume.
>
> The planes can be positioned anywhere.
>
>> In vtk, for example, I can define 6 cropping planes (one parallel to each
>> surface), thus subdividing the volume in 27 rectangular sub-volumes, and
>> switch on or or arbitrary combinations of sub-volumes.
>
> I don't know about being completely arbitrary, but you can certainly do
> something like this with the understanding that each cutting plane defines a
> half-space and successive cutting planes cut the volume in terms of
> half-spaces.
>
Thats just the problem with cutting planes: They always cut the volumes in
half spaces because you cannot restrict their size.
>
>
>
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| Re: Cropping of IDLgrVolume? [message #33840 is a reply to message #33826] |
Fri, 31 January 2003 10:08  |
Karl Schultz
Messages: 341
Registered: October 1999
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Senior Member |
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"Sebastian" <s@visita2.die.upm.es> wrote in message
news:Pine.LNX.4.44.0301311717440.9316-100000@visita2.die.upm .es...
> Hi all,
>
> does anybody know how to crop an IDLgrVolume?
The CUTTING_PLANES property.
As of 5.6, the CLIPPING_PLANES property.
> What I would like to do is this:
> Suppose your volume is a cube, then you can subdivide it into 8 equally
> sized sub-cubes.
> I would like to blend off one of these cubes.
You can use the CUTTING_PLANES property to cut the volume so that only one
of the eight sub-cubes are displayed.
I don't think that you can restrict the extent of the planes to do selective
cutting that might let you remove one sub-cube, leaving the seven others.
Is this what you want?
> And, more advanced, blend off the region of a small cube I position
> somewhere in my original volume.
The planes can be positioned anywhere.
> In vtk, for example, I can define 6 cropping planes (one parallel to each
> surface), thus subdividing the volume in 27 rectangular sub-volumes, and
> switch on or or arbitrary combinations of sub-volumes.
I don't know about being completely arbitrary, but you can certainly do
something like this with the understanding that each cutting plane defines a
half-space and successive cutting planes cut the volume in terms of
half-spaces.
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