Category: FBO, blending, H/W Well, I run a different setting from the previous one I mentioned. I use osg 1.2 (yeah yeah, I promise to upgrade soon). I haven't integrated particle system to my application but I use 1 big billboard with transparency. Until now my FBO cameras used GL_RGBA16F_ARB textures, and also the texture for the billboard was GL_RGBA16F_ARB. I just changed all of them to GL_RGBA32F_ARB and the scene renders correctly. (with transparency). I haven't tried to save the frames to files and check the precision so I've no way to know if the driver didn't fall back to half-float, but I don't believe it would do that anyhow. I'd excpect that if there were troubles they would be the same as yours. But I get solid frame rate of 80+ Hz. (just as before I added the billboard with the blending mode to the scene). Again, I work with nVIDIA 8800 GT, driver 6.14.11.6921, on windows XP.
Do you want to send me .osg scenes, or code that I'll test on my machine? Maybe you ment GL_LUMINANCE_ALPHA32F_ARB format? If so tell me how to set it up instead of the RGBA format and I'll try it. Guy. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of J.P. Delport Sent: Monday, June 02, 2008 2:22 PM To: OpenSceneGraph Users Subject: Re: [osg-users] I get errors when trying to render to a luminance buffer... Hi, (I'm not the guy with the original problem, just interested...) Guy wrote: > Hello, > > > > Category: FBO, blending, H/W > > > > I don't understand exactly what do you mean but H/W blending with float > is not supported. > > I know for sure that we render particle effect with transparency to > float (16bit) FBO, and get the correct results. We also get that with a > decent frame rate (100-200Hz depending on the number of particles). I'm interested in transparency with 32bit floats (alpha blending). Have you tested that? I would like to know if it is supported in hardware. > > > > So I've the feeling that I didn't understand what you mean be blend. > > > > Our H/W is nVIDIA 8800 driver 6.14.11.6921 osg2.0 I think J > > > > I'd appreciate if you clarify your problem. > > Thanks, > > Guy. jp > > > > ------------------------------------------------------------------------ > > *From:* [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] *On Behalf Of *Viggo > L?vli > *Sent:* Monday, June 02, 2008 11:29 AM > *To:* OpenSceneGraph Users > *Subject:* Re: [osg-users] I get errors when trying to render to a > luminance buffer... > > > > Hi again :-) > > I abandoned the idea of using a floating point buffer. > I went into the thinking box and came to the same conclusion as you > wrote about in the end of your comment. > > I needed a quite high resolution so I decided to use all 4 channels > (RGBA). The numbers I want to accumulate is seldom large, so I needed > most resolution in the lower scale. > I thus decided to use RGBA where R is most significant and A is least > significant. > Bit usage is: > R = 6 bits > G = 5 bits > B = 4 bits > A = 3 bits > All non used bits will overlap with next channel. > > I am using this to generate a pixel weight when rendering many > volumetric clouds on top of each other on screen. Naturally most > overlapping clouds will be further away from camera, so I needed as high > a number of overlap bits on the lest significant buffers that I could > get. My usage accepts in worst case 32 overlapping pixels with maximum > weight (in the distance). I think that is something I can live with :-) > > Anyhow, I got a range (18 bit) that was good enough for my usage and it > gives a decent cloud sorting for clouds seen up to 40 kilometers away. > > I must stress one point: > - If you ever try using the alpha channel for this then remember to turn > off alpha-clipping (set alpha-func to always). > > Viggo > > >> Date: Mon, 2 Jun 2008 10:05:24 +0200 >> From: [EMAIL PROTECTED] >> To: [email protected] >> Subject: Re: [osg-users] I get errors when trying to render to a > luminance buffer... >> >> Hi, >> >> Viggo Løvli wrote: >> > Ok, that make sense. >> > It happens every time I render with a floating point texture. >> > >> > The fall in framerate does not happen when I run the OSG multi render >> > target example using HDR. My code does however use additive blending >> > toward the floating point texture so I bet that is what cause it to > fall >> > into a software rendering mode. >> >> We have also experienced this slowdown when blending was enabled with >> float textures. Testing on newer cards is pending as we cannot figure >> out from docs on the internet if this is actually supported in current >> hardware at all. Seems like DX10.1 mandates float blending, but we will >> test to make sure. Please let me know if you know if it is supported in >> hardware. >> >> > >> > Do you know about any texture surface bit format that is more than 8 >> > bits (unsigned integer) ? >> >> I don't know of any. I've only seen a paper once where people were using >> three channels to simulate one large channel. The RGB channels were >> partially overlapped to create a higher dynamic range channel. >> >> jp >> >> > >> > Viggo >> > >> > >> > > Date: Fri, 30 May 2008 16:29:05 +0100 >> > > From: [EMAIL PROTECTED] >> > > To: [email protected] >> > > Subject: Re: [osg-users] I get errors when trying to render to a >> > luminance buffer... >> > > >> > > Hi Viggo, >> > > >> > > When performance drops like this it's because you've dropped onto a >> > > software fallback path in the OpenGL driver. Exactly what formats are >> > > software vs hardware depends upon the hardware and OpenGL drivers. >> > > You'll need to check with your hardware vendors specs to see what will >> > > be hardware accelerated. >> > > >> > > Robert. >> > > >> > > On Fri, May 30, 2008 at 2:16 PM, Viggo Løvli <[EMAIL PROTECTED]> > wrote: >> > > > Hi Robert, >> > > > >> > > > I modified my code as you suggested. >> > > > The warning is gone :-) >> > > > >> > > > The framerate is now 10 seconds per frame instead of 30 frames per >> > second. >> > > > It does something. >> > > > The texture I render to remains black (cleared to black). >> > > > >> > > > If I change the setInternalFormat to GL_RGBA then the framerate is >> > up again, >> > > > and the texture gets colors. This works, but then I only have 8 bit >> > in the >> > > > red channel. What I need is as many bits as possible in the red >> > channel, >> > > > preferably 32. And I do not need GBA channels. >> > > > Do you have a suggestion for me on this one? >> > > > >> > > > Viggo >> > > > >> > > >> Date: Fri, 30 May 2008 13:25:24 +0100 >> > > >> From: [EMAIL PROTECTED] >> > > >> To: [email protected] >> > > >> Subject: Re: [osg-users] I get errors when trying to render to a >> > luminance >> > > >> buffer... >> > > >> >> > > >> Hi Viggo, >> > > >> >> > > >> The warning is exactly right, pbuffers don't suport multiple render >> > > >> targets, only FrameBufferObjects do. >> > > >> >> > > >> Perhaps what you intend it not to use multiple render targets, in >> > > >> which case you should set the Camera attachment to COLOR_BUFFER > rather >> > > >> than COLOR_BUFFER0, that later tells the OSG that you want MRT and >> > > >> will be using glFragColor[] in your shaders. >> > > >> >> > > >> Also the Camera::setDrawBuffer(GL_COLOR_ATTACHMENT0_EXT) is >> > > >> inappropriate for pbuffers. >> > > >> >> > > >> Robert. >> > > >> >> > > >> On Fri, May 30, 2008 at 1:18 PM, Viggo Løvli <[EMAIL PROTECTED]> >> > wrote: >> > > >> > Hi, >> > > >> > >> > > >> > I want to render to a floating point buffer, and I set things up >> > like >> > > >> > this: >> > > >> > >> > > >> > tex->setInternalFormat( GL_LUMINANCE16F_ARB ); >> > > >> > tex->setSourceFormat( GL_RED ); >> > > >> > tex->setSourceType( GL_FLOAT ); >> > > >> > >> > > >> > camera->setRenderTargetImplementation( >> > osg::Camera::FRAME_BUFFER_OBJECT >> > > >> > ); >> > > >> > camera->attach( osg::Camera::BufferComponent( >> > osg::Camera::COLOR_BUFFER0 >> > > >> > ), >> > > >> > tex ); >> > > >> > camera->setDrawBuffer( GL_COLOR_ATTACHMENT0_EXT ); >> > > >> > >> > > >> > My fragment-shader that write to the surface output the value >> > this way: >> > > >> > gl_FragData[0].r = 1.0; >> > > >> > >> > > >> > Another fragment-shader reads the surface this way: >> > > >> > value = texture2DRect( id, gl_FragCoord.xy ).r; >> > > >> > >> > > >> > I get the following output when I try to run my app: >> > > >> > "Warning: RenderStage::runCameraSetUp(state&) Pbuffer does not >> > support >> > > >> > multiple color outputs." >> > > >> > >> > > >> > My app runs, but nothing is written to the texture. >> > > >> > >> > > >> > Is it possible to set up a surface that holds one channel >> > (GL_RED) which >> > > >> > is >> > > >> > an unsigned int of 32 bit resolution? I'd rather use that than a >> > float >> > > >> > :-) >> > > >> > >> > > >> > Viggo >> > > >> > >> > > >> > ________________________________ >> > > >> > Få Hotmail du også. Windows Live Hotmail nå med 5000 MB gratis >> > > >> > lagringsplass. >> > > >> > _______________________________________________ >> > > >> > osg-users mailing list >> > > >> > [email protected] >> > > >> > >> > > >> > >> > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> > > >> > >> > > >> > >> > > >> _______________________________________________ >> > > >> osg-users mailing list >> > > >> [email protected] >> > > >> >> > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> > > > >> > > > >> > > > ________________________________ >> > > > SkyDrive er her. Glem minnepinnen! >> > > > _______________________________________________ >> > > > osg-users mailing list >> > > > [email protected] >> > > > >> > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> > > > >> > > > >> > > _______________________________________________ >> > > osg-users mailing list >> > > [email protected] >> > > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> > >> > ------------------------------------------------------------------------ >> > SkyDrive er her. Glem minnepinnen! <http://skydrive.live.com/?mkt=nb-no> >> > >> > >> > ------------------------------------------------------------------------ >> > >> > _______________________________________________ >> > osg-users mailing list >> > [email protected] >> > > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >> >> -- >> This message is subject to the CSIR's copyright terms and conditions, > e-mail legal notice, and implemented Open Document Format (ODF) standard. >> The full disclaimer details can be found at > http://www.csir.co.za/disclaimer.html. >> >> This message has been scanned for viruses and dangerous content by > MailScanner, >> and is believed to be clean. 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