Dear Maxim I have been thinking about the same things you mentioned in your email, and test 1 is exactly what I plan to do today. I will report back my test results. Thanks!
Jinghua On Thu, Feb 19, 2009 at 2:55 AM, Maxim Makhinya <[email protected]> wrote: > > Hello Jinghua, > > This part of your code looks correct, I never tried it > with GL_LUMINANCE thought. How I would approach you > problem is the following: > > 1) Create same test cases for ranges [0 1] and [0 0.25]. > Which means that for one of them you HAVE TO adjust > depth scaling in your .vhf file ( dScale=..). When > you render your two cases, make sure objects occupy > exactly the SAME space on the screen, and that final > rendering is identical (make also sure you are using > the same number of intersecting slices). This is very > important since volume rendering performance directly > depends on your fill, i.e. how many pixels were > rendered, cause all the job is done by fragment shader! > > 2) analyze then 3D textures' sizes, they should be > identical (you render the same data). > > I don't see why you have this problems, because when you > have range [0 0.25] sliceClipping ( sliceClipping.cpp ) will > cut a parallelepiped out of the cube (1,1,1) and your texture > coordinates will also be in range: (0..1, 0..1, 0..0.25), > but, your texture fits perfectly in to > (0..1024, 0..1024, 0..256), and you want to use the whole > texture, not just the first quarter of it, so TD.D will be > 4, and it will rescale coordinates from sliceClipping to > (0..1, 0..1, 0..1), but on the screen it will still look as > parallelepiped! Now if you render same amount of data but > using different ranges [0 1] and [0 0.25] one will look as > a cube and another as parallelepiped (if scaling coefficients > are equal), that's why you need to readjust them for one of > your test cases; again, you need exactly the same data and > exactly the same screen space to be rendered to compare > performance, it is not enough just to simply render same > amount of data. > > > Best Regards, > > Makhinya Maxim > > > On Feb 18, 2009, at 6:28 PM, Jinghua Ge wrote: > > > Yes I see 1/4 data scaled to the same screen space. I am pretty sure > > I load the same amount of data into 3D texture, as the print out > > shows: w:1024 1024 h:1024 1024 d:1024 256 256 > > > > The texture code is: (I set comp = 1 for my ubyte volume data) > > > > if(comp == 4) > > { > > glTexImage3D( GL_TEXTURE_3D, > > 0, GL_RGBA, tW, tH, tD, > > 0, GL_RGBA, GL_UNSIGNED_BYTE, (GLvoid*) > > (&data[0]) ); > > } > > else if(comp == 1) > > { > > //glTexImage3D( GL_TEXTURE_3D, > > // 0, GL_ALPHA, tW, tH, tD, > > // 0, GL_ALPHA, GL_UNSIGNED_BYTE, (GLvoid*) > > (&data[0]) ); > > glTexImage3D( GL_TEXTURE_3D, > > 0, GL_LUMINANCE, tW, tH, tD, > > 0, GL_LUMINANCE, GL_UNSIGNED_BYTE, (GLvoid*) > > (&data[0]) ); > > } > > > > Let me double check tho. > > > > > > Jinghua > > > > > > On Wed, Feb 18, 2009 at 11:20 AM, Maxim Makhinya > > <[email protected]> wrote: > > > > > >> I set the TD.D = 1. , the rendering is fast now, but the > > >> scaling is wrong. > > > > > > Doing this you should see wrong portion of data rendered, not > > > wrong scaled! > > > > well, actually, you will see both - wrong scaled and wrong > > portion ( 4 times smaller ) of data, because smaller portion > > will occupy same screen space (if you didn't messed vertex > > positions). > > > > _______________________________________________ > > eq-dev mailing list > > [email protected] > > http://www.equalizergraphics.com/cgi-bin/mailman/listinfo/eq-dev > > http://www.equalizergraphics.com > > > > > > > > -- > > Jinghua Ge, Ph.D > > Visualization Consultant, CCT > > 331 Frey Computing Services Center > > Louisiana State University > > Phone: (225) 578-7789 > > Fax: (225) 334-2061 > > > > > > _______________________________________________ > > eq-dev mailing list > > [email protected] > > http://www.equalizergraphics.com/cgi-bin/mailman/listinfo/eq-dev > > http://www.equalizergraphics.com > > > _______________________________________________ > eq-dev mailing list > [email protected] > http://www.equalizergraphics.com/cgi-bin/mailman/listinfo/eq-dev > http://www.equalizergraphics.com > -- Jinghua Ge, Ph.D Visualization Consultant, CCT 331 Frey Computing Services Center Louisiana State University Phone: (225) 578-7789 Fax: (225) 334-2061
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