[vtkusers] Re: vtkusers digest, Vol 1 #1492 - 6 msgs

liuxiaoning lxn at cnv-it.com
Sat Dec 28 00:58:14 EST 2002


Hi to all,

I'am wandering if VTK can Support 3D restructure in any way?

Who can tell me about this?

Many thanks!
----- Original Message ----- 
From: <vtkusers-request at public.kitware.com>
To: <vtkusers at public.kitware.com>
Sent: Friday, December 27, 2002 7:39 PM
Subject: vtkusers digest, Vol 1 #1492 - 6 msgs


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> Today's Topics:
> 
>    1. Re: Starbase support on HP workstations (Will Schroeder)
>    2. Re: Starbase support on HP workstations (Lakmal.Gunasekara at t-online.de)
>    3. SetResliceAxesDirectionCosines (=?iso-8859-1?q?sebastien?=)
>    4. Re: SetResliceAxesDirectionCosines (David Gobbi)
>    5. RE: vtkRayCaseVolume mapper in VTK 4.0 (Lisa S. Avila)
>    6. vtkPointPicker2D (K.R.Subramanian)
> 
> --__--__--
> 
> Message: 1
> Date: Thu, 26 Dec 2002 09:51:54 -0500
> To: Lakmal.Gunasekara at t-online.de, vtkusers at public.kitware.com
> From: Will Schroeder <will.schroeder at kitware.com>
> Subject: Re: [vtkusers] Starbase support on HP workstations
> 
> Starbase support was obsoleted several releases back. You'll have to dig up 
> a very old version of VTK to get starbase support.
> 
> Will
> 
> At 09:17 PM 12/25/2002 +0100, Lakmal.Gunasekara at t-online.de wrote:
> >Hi to all,
> >
> >I'm compiling VTK R.4.0 on my HP workstation und HP-UX 10.20.
> >
> >I wonder why the OpenGL header files are included and why it links with
> >the OpenGL library.
> >
> >I've expected that VTK uses the Starbase library on HP platforms for
> >visualization (that's what I've read in the provided papers). My
> >graphics subsystem does not support 3D acceleration via OpenGL but
> >there is 3D support (even with Stereo viewing) for the Starbase
> >library. So I want to use that instead of OpenGL.
> >
> >Do I have to reconfigure VTK in some way so that it does not use
> >OpenGL? I've done a cmake -i with advanced options==yes but I didn't
> >see a cmake question concerning the Starbase libraries/include files,
> >it only asks for the OpenGL stuff.
> >
> >Could someone please give me a hint how to turn on the Starbase
> >support?
> >
> >Thanks in advance,
> >
> >Lakmal
> >_______________________________________________
> >This is the private VTK discussion list.
> >Please keep messages on-topic. Check the FAQ at: 
> ><http://public.kitware.com/cgi-bin/vtkfaq>
> >Follow this link to subscribe/unsubscribe:
> >http://public.kitware.com/mailman/listinfo/vtkusers
> 
> 
> 
> 
> --__--__--
> 
> Message: 2
> To: vtkusers at public.kitware.com
> Subject: Re: [vtkusers] Starbase support on HP workstations
> From: Lakmal.Gunasekara at t-online.de
> Date: Thu, 26 Dec 2002 19:27:46 +0100 (CET)
> 
> Hi Will,
> 
> thanks for your fast response.
> 
> > Starbase support was obsoleted several releases back.
> 
> Hm. What was the historical reason for that? As far as I understood the
> concept of VTK correctly one of its benefits is the hardware/rendering
> API abstraction. But at the moment you only support OpenGL, correct?
> 
> > You'll have to dig up 
> > a very old version of VTK to get starbase support.
> 
> How do I do that (name of the CVS tag)? Do you know which was the last
> version of VTK with Starbase support?
> 
> Thanks,
> 
> Lakmal
> 
> --__--__--
> 
> Message: 3
> Date: Thu, 26 Dec 2002 20:11:17 +0100 (CET)
> From: =?iso-8859-1?q?sebastien?= <sebastien_gd at yahoo.fr>
> To: vtkusers at public.kitware.com
> Subject: [vtkusers] SetResliceAxesDirectionCosines
> 
> Hello
> I want to make a slice of a volume. So I use the
> methods SetResliceAxesDirectionCosines and
> SetResliceAxesOrigin of vtkImageResllice.
> I want to know why we must define 3 axes in this
> method whereas it is possible to define a plane with 2
> axes.
> By passing randomly the arguments of this method, I
> have obtained a slice but I want to make a slice of a
> precise plane.
> 
> Thank you
> 
> 
> ___________________________________________________________
> Do You Yahoo!? -- Une adresse @yahoo.fr gratuite et en français !
> Yahoo! Mail : http://fr.mail.yahoo.com
> 
> --__--__--
> 
> Message: 4
> Date: Thu, 26 Dec 2002 20:25:06 -0500 (EST)
> From: David Gobbi <dgobbi at imaging.robarts.ca>
> To: =?iso-8859-1?q?sebastien?= <sebastien_gd at yahoo.fr>
> Cc: vtkusers at public.kitware.com
> Subject: Re: [vtkusers] SetResliceAxesDirectionCosines
> 
> Hi Sebastien,
> 
> The SetResliceAxesDirectionCosines() takes 3 vectors to make the
> class more general, i.e. to allow a person to specify the x,y,z
> axes of an output volume.  For a single slice, take the cross
> product of the x and y vectors to get a z vector.  Then, use
> SetResliceAxesOrigin() to specify a point that lies on the slice
> plane.
> 
>  - David
> 
> --
>   David Gobbi, MSc                dgobbi at imaging.robarts.ca
>   Advanced Imaging Research Group
>   Robarts Research Institute, University of Western Ontario
> 
> On Thu, 26 Dec 2002, [iso-8859-1] sebastien wrote:
> 
> > Hello
> > I want to make a slice of a volume. So I use the
> > methods SetResliceAxesDirectionCosines and
> > SetResliceAxesOrigin of vtkImageResllice.
> > I want to know why we must define 3 axes in this
> > method whereas it is possible to define a plane with 2
> > axes.
> > By passing randomly the arguments of this method, I
> > have obtained a slice but I want to make a slice of a
> > precise plane.
> >
> > Thank you
> >
> >
> > ___________________________________________________________
> > Do You Yahoo!? -- Une adresse @yahoo.fr gratuite et en fran=E7ais !
> > Yahoo! Mail : http://fr.mail.yahoo.com
> > _______________________________________________
> > This is the private VTK discussion list.
> > Please keep messages on-topic. Check the FAQ at: <http://public.kitware.c=
> om/cgi-bin/vtkfaq>
> > Follow this link to subscribe/unsubscribe:
> > http://public.kitware.com/mailman/listinfo/vtkusers
> >
> 
> 
> --__--__--
> 
> Message: 5
> Date: Fri, 27 Dec 2002 01:33:08 -0500
> To: "Alex Romadinoff" <alexeyr at netcracker.com>,
> "'Bill Lorensen'" <wlorens1 at nycap.rr.com>,
> "'Amy Henderson'" <amy.henderson at kitware.com>,
> <vtkusers at public.kitware.com>
> From: "Lisa S. Avila" <lisa.avila at kitware.com>
> Subject: RE: [vtkusers] vtkRayCaseVolume mapper in VTK 4.0
> 
> Hello,
> 
> The main issue is that the transfer function is sampled into an array, and 
> the array is indexed by the scalar value during rendering. To have this 
> work with signed data we must add an offset to the scalar value to use it 
> as an index (since we can't index with negative values). This is fairly 
> straightforward, and should be done with both a scale and a bias to support 
> bigger data (unsigned short leads to an array with 65535 elements - more 
> than this would not be a good idea so a scale is needed to handle integer 
> data).  This change has been on my list of "things to do when I get some 
> time" for a few years now..... :-)
> 
> Lisa
> 
> 
> 
> 
> At 04:39 AM 12/23/2002, Alex Romadinoff wrote:
> >Bill,
> >
> >Thank you for answer.
> >It seams to be very reasonable. In fact if other types are permitted,
> >mapper should implement improper function of data filtering, i.e.
> >negative data to something meaningful translation. So this translation
> >should be performed in color transfer function, but such solution breaks
> >vtkPiecewiseFunction usage for opacity idiom, so present solution is
> >very rational.
> >
> >But the problem is that the solution isn't documented :(
> >
> >Alex
> >
> >-----Original Message-----
> >From: Bill Lorensen [mailto:wlorens1 at nycap.rr.com]
> >Sent: Saturday, December 21, 2002 12:39 AM
> >To: Alex Romadinoff; 'Amy Henderson'; vtkusers at public.kitware.com
> >Subject: RE: [vtkusers] vtkRayCaseVolume mapper in VTK 4.0
> >
> >Alex,
> >
> >There is really not a good justification for the limitation. I believe
> >the concern is that the transfer functions cannot handle negative
> >independent variables, but this, in my opinion, is an implementation
> >flaw.
> >
> >Although I'm not a volume rendering guy, one of these days, I'll remove
> >this limitation...
> >
> >Bill
> >
> >
> >At 09:49 PM 12/20/02 +0300, Alex Romadinoff wrote:
> > >But what's the reason for such limitations?
> > >
> > >Alex
> > >
> > >-----Original Message-----
> > >From: Amy Henderson [mailto:amy.henderson at kitware.com]
> > >Sent: Friday, December 20, 2002 9:44 PM
> > >To: Alex Romadinoff; vtkusers at public.kitware.com
> > >Subject: Re: [vtkusers] vtkRayCaseVolume mapper in VTK 4.0
> > >
> > >At 09:42 PM 12/20/2002 +0300, Alex Romadinoff wrote:
> > >>Dear all,
> > >>
> > >>I try to render volume data with the following code
> > >>
> > >>// :skipped:
> > >>short* data=new short [1000000];
> > >>
> > >>  for (int i=0; i<1000000; i++){
> > >>      data[i]=120+200*sin(i)*((i+1)%20);
> > >>  }
> > >>
> > >>  vtkImageImport *img=vtkImageImport::New();
> > >>
> > >>  img->SetImportVoidPointer (data);
> > >>  img->SetDataScalarTypeToShort ();
> > >>  img->SetWholeExtent (0, 100, 0, 100, 0, 100);
> > >>  img->SetDataExtentToWholeExtent ();
> > >>// ..skipped..
> > >>vtkVolumeRayCastMapper* volumeMapper=vtkVolumeRayCastMapper::New();
> > >>volumeMapper->SetVolumeRayCastFunction (compositeFunction);
> > >>volumeMapper->SetInput (img->GetOutput());
> > >>// ..skipped
> > >>
> > >>When I use short or double type for data array and do
> > >>SetDataScalarTypeTo{Short|Double} the resultant rendered image is
> > >empty.
> > >>
> > >>When I use unsigned char for data transition, volume is visualized
> > >well.
> > >>
> > >>What's up ?
> > >>Is vtkVolumeRayCastMapper works only for unsigned char data ?
> > >
> > >It will handle unsigned char or unsigned short data.
> > >- Amy
> > >
> > >>With best wishes,
> > >>Alex
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>_______________________________________________
> > >>This is the private VTK discussion list.
> > >>Please keep messages on-topic. Check the FAQ at:
> > >><http://public.kitware.com/cgi-bin/vtkfaq>
> > >>Follow this link to subscribe/unsubscribe:
> > >>http://public.kitware.com/mailman/listinfo/vtkusers
> > >
> > >
> > >
> > >_______________________________________________
> > >This is the private VTK discussion list.
> > >Please keep messages on-topic. Check the FAQ at:
> ><http://public.kitware.com/cgi-bin/vtkfaq>
> > >Follow this link to subscribe/unsubscribe:
> > >http://public.kitware.com/mailman/listinfo/vtkusers
> >
> >_______________________________________________
> >This is the private VTK discussion list.
> >Please keep messages on-topic. Check the FAQ at: 
> ><http://public.kitware.com/cgi-bin/vtkfaq>
> >Follow this link to subscribe/unsubscribe:
> >http://public.kitware.com/mailman/listinfo/vtkusers
> 
> 
> 
> 
> --__--__--
> 
> Message: 6
> Date: Fri, 27 Dec 2002 01:39:44 -0500
> From: "K.R.Subramanian" <krs at cs.uncc.edu>
> Organization: Univ. of N. Carolina at Charlotte
> To: VTK HELP <vtkusers at public.kitware.com>
> Subject: [vtkusers] vtkPointPicker2D
> 
> 
> I was trying to use this picker as I was operating on 2D images. But it consistently
> returns a point id of -1, when asked to determine the closest point..
> 
> I switched to vtkPointPicker and it works fine(of course zeroing out the z coordinate).
> I  am missing something here.. the 2D version should be more efficient..
> 
> Thanks.
> 
>     -- krs
> 
> --
> K.R.Subramanian                        Phone: (704) 687-4872
> Department of Computer Science         FAX:   (704) 687-4893
> UNC Charlotte, CARC 311                Email: krs at cs.uncc.edu
> Charlotte, NC 28223-0001               Web: http://www.cs.uncc.edu/~krs
> 
> 
> 
> 
> 
> --__--__--
> 
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