Re: [osg-users] Float textures seem to be clamped in GLSL
Hi, Thrall, Bryan wrote: Brian R Hill wrote on Wednesday, March 04, 2009 5:41 PM: // disable clamping osg::ClampColor* clamp = new osg::ClampColor(); clamp->setClampVertexColor(GL_FALSE); clamp->setClampFragmentColor(GL_FALSE); clamp->setClampReadColor(GL_FALSE); scene->getOrCreateStateSet()->setAttribute(clamp, osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE); I am sad to report that that doesn't work either :( Is there something I'm doing wrong with osg::TransferFunction1D, or is my understanding wrong? I'm not familiar with osg::TransferFunction1D, but I'm sure that float texture data can reach shaders without clamping, we use it all the time. I'd suggest creating an osg::Image that is attached to a texture and see if the values then work properly, you can modify the image data directly. Have a look at the osgprerender example when the options --hdr and --image are enabled. There are e.g. negative values in the image. jp -- 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. MailScanner thanks Transtec Computers for their support. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Float textures seem to be clamped in GLSL
Brian R Hill wrote on Wednesday, March 04, 2009 5:41 PM: > // disable clamping > osg::ClampColor* clamp = new osg::ClampColor(); > clamp->setClampVertexColor(GL_FALSE); > clamp->setClampFragmentColor(GL_FALSE); > clamp->setClampReadColor(GL_FALSE); > scene->getOrCreateStateSet()->setAttribute(clamp, osg::StateAttribute::ON | > osg::StateAttribute::OVERRIDE); I am sad to report that that doesn't work either :( > -osg-users-boun...@lists.openscenegraph.org wrote: - > > To: "OpenSceneGraph Users" > From: "Thrall, Bryan" > Sent by: osg-users-boun...@lists.openscenegraph.org > Date: 03/04/2009 05:05PM > Subject: [osg-users] Float textures seem to be clamped in GLSL > > > I'm rather new to using float textures and GLSL, so maybe I'm missing > something. I'm trying to use a float texture as a lookup table in my > fragment shader. I create the texture using osg::TransferFunction1D (see > attached modified osgviewer.cpp), and use the following in my input > file: > > ---8<--- > 50 > 0 0 0 > 0 0 50 > ---8<--- > > For example: osgviewer --pos implicit.pos implicit_surface.osg > (the shaders need to be in a shaders/ subdirectory under > implicit_surface.osg's directory) > > My shader takes these positions and renders implicit spheres around > them, with the first line of the position file being the radius. > > However, the positions seem to be clamped to [0,1], since the resulting > spheres overlap except for a little bit at the edge (changing the radius > to 1 shows their centers are 1 unit apart). My understanding is that > float textures should be passed through to the shader without clamping. > > Is there something I'm doing wrong with osg::TransferFunction1D, or is > my understanding wrong? > > Thanks, -- Bryan Thrall FlightSafety International bryan.thr...@flightsafety.com ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Float textures seem to be clamped in GLSL
Bryan, I've used this: // disable clamping osg::ClampColor* clamp = new osg::ClampColor(); clamp->setClampVertexColor(GL_FALSE); clamp->setClampFragmentColor(GL_FALSE); clamp->setClampReadColor(GL_FALSE); scene->getOrCreateStateSet()->setAttribute(clamp, osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE); Brian This is a PRIVATE message. If you are not the intended recipient, please delete without copying and kindly advise us by e-mail of the mistake in delivery. NOTE: Regardless of content, this e-mail shall not operate to bind CSC to any order or other contract unless pursuant to explicit written agreement or government initiative expressly permitting the use of e-mail for such purpose. • -osg-users-boun...@lists.openscenegraph.org wrote: - To: "OpenSceneGraph Users" From: "Thrall, Bryan" Sent by: osg-users-boun...@lists.openscenegraph.org Date: 03/04/2009 05:05PM Subject: [osg-users] Float textures seem to be clamped in GLSL I'm rather new to using float textures and GLSL, so maybe I'm missing something. I'm trying to use a float texture as a lookup table in my fragment shader. I create the texture using osg::TransferFunction1D (see attached modified osgviewer.cpp), and use the following in my input file: ---8<--- 50 0 0 0 0 0 50 ---8<--- For example: osgviewer --pos implicit.pos implicit_surface.osg (the shaders need to be in a shaders/ subdirectory under implicit_surface.osg's directory) My shader takes these positions and renders implicit spheres around them, with the first line of the position file being the radius. However, the positions seem to be clamped to [0,1], since the resulting spheres overlap except for a little bit at the edge (changing the radius to 1 shows their centers are 1 unit apart). My understanding is that float textures should be passed through to the shader without clamping. Is there something I'm doing wrong with osg::TransferFunction1D, or is my understanding wrong? Thanks, -- Bryan Thrall FlightSafety International bryan.thr...@flightsafety.com ___ 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
Re: [osg-users] Float textures seem to be clamped in GLSL
David Spilling wrote on Wednesday, March 04, 2009 5:06 PM: > My initial thought was that nowhere were you saying that the image was > floating point. Digging further, I realised that TransferFunction should be > doing it for you - I've never used this before - but this line (in > osg/TransferFunction1D.cpp) looks a little odd to me: > > _image->setImage(numX,1,1,GL_RGBA, GL_RGBA, GL_FLOAT, (unsigned > char*)&_colors[0], osg::Image::NO_DELETE); > > Shouldn't that be "GL_RGBA32F_ARB,GL_RGBA, GL_FLOAT"? > > I guess also doing a texture1D->setInternalFormat(GL_RGBA32F_ARB) might help, > but I think (without looking at the code) that osg probably picks this up > from the image format anyway. I think you're using an older OSG version than I do, since I've only got TransferFunction.cpp, and TransferFunction1D uses image->allocateImage(), but either way, setting the Image internal format to GL_RGBA32F_ARB doesn't help. I should also note that I'm running an NVIDIA 8800 GT on Windows (compiled with VS 2005), and osgviewer reports I have ARB_texture_float supported. -- Bryan Thrall FlightSafety International bryan.thr...@flightsafety.com ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Float textures seem to be clamped in GLSL
Bryan, My initial thought was that nowhere were you saying that the image was floating point. Digging further, I realised that TransferFunction should be doing it for you - I've never used this before - but this line (in osg/TransferFunction1D.cpp) looks a little odd to me: _image->setImage(numX,1,1,GL_RGBA, GL_RGBA, GL_FLOAT, (unsigned char*)&_colors[0], osg::Image::NO_DELETE); Shouldn't that be "GL_RGBA32F_ARB,GL_RGBA, GL_FLOAT"? I guess also doing a texture1D->setInternalFormat(GL_RGBA32F_ARB) might help, but I think (without looking at the code) that osg probably picks this up from the image format anyway. Hope that helps. David ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] Float textures seem to be clamped in GLSL
I'm rather new to using float textures and GLSL, so maybe I'm missing something. I'm trying to use a float texture as a lookup table in my fragment shader. I create the texture using osg::TransferFunction1D (see attached modified osgviewer.cpp), and use the following in my input file: ---8<--- 50 0 0 0 0 0 50 ---8<--- For example: osgviewer --pos implicit.pos implicit_surface.osg (the shaders need to be in a shaders/ subdirectory under implicit_surface.osg's directory) My shader takes these positions and renders implicit spheres around them, with the first line of the position file being the radius. However, the positions seem to be clamped to [0,1], since the resulting spheres overlap except for a little bit at the edge (changing the radius to 1 shows their centers are 1 unit apart). My understanding is that float textures should be passed through to the shader without clamping. Is there something I'm doing wrong with osg::TransferFunction1D, or is my understanding wrong? Thanks, -- Bryan Thrall FlightSafety International bryan.thr...@flightsafety.com osgviewer.cpp Description: osgviewer.cpp implicit_surface.vert Description: implicit_surface.vert implicit_surface.frag Description: implicit_surface.frag implicit_surface.osg Description: implicit_surface.osg ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
