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.
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. Ideally, I would want to emulate something along the lines of this: http://www.cemuva.com/img/uploads/malformacion-arteriovenosa-cerebral-3d.jpg <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] > <mailto:[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] >> <mailto:[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 <tel:518-881-4909> >> On Mon, Sep 21, 2015 at 9:40 AM, Mathew Guilfoyle <[email protected] >> <mailto:[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 <http://www.kitware.com/> >> >> Visit other Kitware open-source projects at >> http://www.kitware.com/opensource/opensource.html >> <http://www.kitware.com/opensource/opensource.html> >> >> Please keep messages on-topic and check the ParaView Wiki at: >> http://paraview.org/Wiki/ParaView <http://paraview.org/Wiki/ParaView> >> >> Search the list archives at: http://markmail.org/search/?q=ParaView >> <http://markmail.org/search/?q=ParaView> >> >> Follow this link to subscribe/unsubscribe: >> http://public.kitware.com/mailman/listinfo/paraview >> <http://public.kitware.com/mailman/listinfo/paraview> >> > > > _______________________________________________ > Powered by www.kitware.com <http://www.kitware.com/> > > Visit other Kitware open-source projects at > http://www.kitware.com/opensource/opensource.html > <http://www.kitware.com/opensource/opensource.html> > > Please keep messages on-topic and check the ParaView Wiki at: > http://paraview.org/Wiki/ParaView <http://paraview.org/Wiki/ParaView> > > Search the list archives at: http://markmail.org/search/?q=ParaView > <http://markmail.org/search/?q=ParaView> > > Follow this link to subscribe/unsubscribe: > http://public.kitware.com/mailman/listinfo/paraview > <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>
_______________________________________________ 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
