Hi Clement, I really don't know what is going on at your end, what you are expecting, what you've coded, there is no way I can provide any answers.
Robert. On 18 January 2012 17:31, <clement....@csiro.au> wrote: > HI Robert, > > I replaced the program from coin to osg and I don't know why osg display > the image from the same volume data is different from coin. I think the > problem is on texture format since I changed to use different parameter of > texture format such as GL_RGBA, GL_RGB16F_ARB, GL_RGBA8. The display images > are different. When GL_RGB16F_ARB is used, the colour is closer to I > expected, but I have no idea why the volume body is empty (1st attached > file). When GL_RGBA is used, the body of volume is filled, but the colour is > not sharp enough. I don't know how to set to use the right texture > parameter. Sorry for my worse explanation. Hope this time better. Thanks. > > > Regards, > Clement > > ________________________________________ > From: osg-users-boun...@lists.openscenegraph.org > [osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield > [robert.osfi...@gmail.com] > Sent: Thursday, 19 January 2012 4:15 AM > To: OpenSceneGraph Users > Subject: Re: [osg-users] osgvolume opacity settings > > Hi Clement, > > I can't work out specifically what you are expecting to happen. What > coin does is something I have no experience with so can't comment on > how you might try to obtain a similar image. > > Robert. > > On 18 January 2012 15:14, <clement....@csiro.au> wrote: >> Hi Robert, >> >> Thanks for your reply. I found the problem may relate to the texture >> format when called setImage. I attached three images to describe my >> problem. The image texture_GL_RGBA.jpg is used GL_RGBA for the 4th >> parameter in setImage. >> >> eg. osgImage->setImage(nx, ny, nz, GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE, >> (uint8*)pdisp), osg::Image::NO_DELETE); >> >> >> The image texture_GL_RGB16F_ARB.jpg is used GL_RGB16F_ARB parameter. The >> colour of this image is I expected, but the problem is that this image is no >> body (only surface have colour). If I used GL_RGBA, it can fill in the >> whole volume, but the colour is very light and blur. The last attachment is >> captured from coin3d library and it is my original render library. Now I >> have replaced with osg, so I expect the osg can display the same result as >> coin3d. >> >> From the first two images, do you know which texture format parameter I >> should use? Thanks. >> >> >> Regards, >> Clement >> >> ________________________________________ >> From: osg-users-boun...@lists.openscenegraph.org >> [osg-users-boun...@lists.openscenegraph.org] On Behalf Of Robert Osfield >> [robert.osfi...@gmail.com] >> Sent: Monday, 16 January 2012 8:21 PM >> To: OpenSceneGraph Users >> Subject: Re: [osg-users] osgvolume opacity settings >> >> Hi Clement, >> >> On 16 January 2012 06:21, <clement....@csiro.au> wrote: >>> My application is using osgvolume to display CT data. There is class >>> called CompositeProperty and there are three property classes >>> (AlphaFuncProperty, SampleDensityProperty and TransparencyProperty) as >>> well. I would like to know more details of those classes and how to apply >>> on osgvolume. I did to follow the example to use those classes, but when I >>> changed the value of SampleDensityProperty from 0.05 to 0.5. Some CT data >>> are disappear, so I would like to know more how to control property values. >>> Many thanks. >> >> AlphaFuncProperty is equivalent to glAlphaFunc and sets the alpha >> value below which fragments will be discarded >> >> TransparencyProperty is an alpha value multiplier that you can use to >> make your volume more transparent. >> >> SampleDensityProperty controls the size of the step during the ray >> tracing through the volume, the lower the value >> the more samples, the higher the value the less the samples. If you >> use a value of 0.5 you'll only get 3 samples which clearly won't be >> enough! >> >> Robert. >> _______________________________________________ >> osg-users mailing list >> osg-users@lists.openscenegraph.org >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> >> _______________________________________________ >> osg-users mailing list >> osg-users@lists.openscenegraph.org >> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
