On Wed, Sep 23, 2015 at 3:34 PM, Mathew Guilfoyle <[email protected]> wrote:
> Aashish - thanks for the reply > > I am using the latest OS X binary download (4.4.0) - is this OpenGL2? > When I switch ‘Volume Rendering Mode’ to GPU rendering all images disappear > so I presume I’m only able to use CPU rendering. I am on a 2014 Macbook > Pro with Nvidia GT750M. > No it would be OpenGL old version VTK. It would be nice if you can try OpenGL2 version although I don't think your problem is related to GL version. > > I’m using contrast enhanced volumetric CT imaging. I want to render blood > vessels in red; within the scan they appear in approximately the 100-200 > Hounsfield unit range. The full range of scalar data is [-1024, 3071]. On > this basis I’ve set up the following colour and opacity mappings: > > Colour: > Value R-G-B > -1024 0-0-0 > 99 0-0-0 > 100 1-0-0 > 200 1-0-0 > 201 0-0-0 > 3071 0-0-0 > > Opacity: > Value Opacity > -1024 0 > 99 0 > 100 1 > 200 1 > 201 0 > 3071 0 > > None of the voxels appear to be fully opaque in the rendering. When I > increase the specular from 0 to 1 it has no effect at all on the image. > > Have you enabled the lighting? http://www.vtk.org/doc/nightly/html/classvtkVolumeProperty.html (ShadeOn) on volume property? - Aashish > Ideally, I would want to emulate something along the lines of this: > http://www.cemuva.com/img/uploads/malformacion-arteriovenosa-cerebral-3d.jpg > > Again, cheers for the help > Mathew > > On 23 Sep 2015, at 18:24, Aashish Chaudhary <[email protected]> > wrote: > > Matthew, > > * Can you send us the exact number you are putting in for the transfer > function? Make sure that you have values for the entire range of scalar > values? > > * Are you using OpenGL2 version? > > - Aashish > > On Wed, Sep 23, 2015 at 1:18 PM, Mathew Guilfoyle <[email protected]> > wrote: > >> Thanks for the suggestions. After looking into it further the type of >> visualisation I am after is volume rendering of the data with an opacity >> transfer function based on the scalar data values. >> >> I have set up my volume rendering to have full (i.e =1) opacity through >> the range of scalar values I’m interested in, reducing to near transparency >> either side of this. I also want specular highlighting of the opaque >> tissues. >> >> However, despite these settings Paraview does not seem to render any >> voxels as fully opaque and there is certainly no specular highlighting. Is >> this a known limitation? >> >> Many thanks >> >> On 21 Sep 2015, at 15:10, David E DeMarle <[email protected]> >> wrote: >> >> Two suggestions: >> * try contour filter instead of threshold if contour isn't available, >> apply cell to point first. >> * try the clip filter with the clip type set to scalar. >> hth >> >> David E DeMarle >> Kitware, Inc. >> R&D Engineer >> 21 Corporate Drive >> Clifton Park, NY 12065-8662 >> Phone: 518-881-4909 >> >> On Mon, Sep 21, 2015 at 9:40 AM, Mathew Guilfoyle <[email protected]> >> wrote: >> >>> I would be grateful for some advice on volume and surface rendering in >>> Paraview. >>> >>> I am trying to generate 3D skull models from CT data. The reason for >>> using Paraview is to take advantage of the detailed fly-through/movie >>> capability. I can generate an acceptable 3D model that I can interact with >>> in OsiriX and 3D Slicer, both of which I believe use VTK. However, in >>> Paraview I am struggling to create a 3D model that looks any good. >>> >>> When I apply a threshold filter and view as a ‘Surface’ the image is a >>> lot more ‘blocky’ than in the other two applications. The image is >>> dominated by the artifactual lines due to the original data being acquired >>> as axial slices; whereas in OsiriX and 3D Slicer this gets smoothed out and >>> the ‘genuine’ surface skull features (sutures etc) stand out. >>> >>> I realise this is probably question of apply the correct series of >>> filters and that the other two apps do this ‘under the hood’. However, i >>> have tried to apply Decimation and Smooth to the extracted surface and am >>> not making any headway. >>> >>> Any pointers would be very welcome >>> >>> M >>> _______________________________________________ >>> Powered by www.kitware.com >>> >>> Visit other Kitware open-source projects at >>> http://www.kitware.com/opensource/opensource.html >>> >>> Please keep messages on-topic and check the ParaView Wiki at: >>> http://paraview.org/Wiki/ParaView >>> >>> Search the list archives at: http://markmail.org/search/?q=ParaView >>> >>> Follow this link to subscribe/unsubscribe: >>> http://public.kitware.com/mailman/listinfo/paraview >>> >> >> >> >> _______________________________________________ >> Powered by www.kitware.com >> >> Visit other Kitware open-source projects at >> http://www.kitware.com/opensource/opensource.html >> >> Please keep messages on-topic and check the ParaView Wiki at: >> http://paraview.org/Wiki/ParaView >> >> Search the list archives at: http://markmail.org/search/?q=ParaView >> >> Follow this link to subscribe/unsubscribe: >> http://public.kitware.com/mailman/listinfo/paraview >> >> > > > -- > > > > *| Aashish Chaudhary | Technical Leader | Kitware Inc. * > *| http://www.kitware.com/company/team/chaudhary.html > <http://www.kitware.com/company/team/chaudhary.html>* > > > -- *| Aashish Chaudhary | Technical Leader | Kitware Inc. * *| http://www.kitware.com/company/team/chaudhary.html <http://www.kitware.com/company/team/chaudhary.html>*
_______________________________________________ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Please keep messages on-topic and check the ParaView Wiki at: http://paraview.org/Wiki/ParaView Search the list archives at: http://markmail.org/search/?q=ParaView Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/paraview
