Hi, Thanks!
I tried that a moment ago. The results are still filtered. What about the internal mode of the image? There are just so many of them. Shuiying On 09/04/2014 02:15 PM, [email protected] wrote:
Message: 10 Date: Thu, 4 Sep 2014 14:15:52 +0200 From: Christian Buchner<[email protected]> To: OpenSceneGraph Users<[email protected]> Subject: Re: [osg-users] Help: how to send non-filtered sampler2Drect to fragment shader? Message-ID: <CALm6U+o22xDgKEtpUkKhHuUOG=h8q7zPTTQ=8r9tz-1Ft=a...@mail.gmail.com> Content-Type: text/plain; charset="utf-8" Hi, have you tried also setting the minification filter to NEAREST? osg::Texture2D::MIN_FILTER Christian 2014-09-04 13:14 GMT+02:00 shuiying Wang<[email protected]>:> Hello, > >I would like the fragment shader to read values from a uniform >sampler2DRect. > >The sampler2DRect stores some data that I want to give to the shader. > >The problem is that the shader always gets filtered value of the actual >data. I want the shader to get the exact value without any filtering. > >I use the following binding method and shader programming: > >//set image > >osg::ref_ptr<osg::Image> imageSampler = new osg::Image(); > > >imageSampler->allocateImage((int)XRes, (int)YRes, 1, GL_RGBA, GL_FLOAT); > >osg::Vec4f * rgba = (osg::Vec4f *)(imageSampler->data()); > > // write date to the image > >for (int row = 0; row < subYRes; row++) { > > for (int column = 0; column < subXRes; > < >span style="color:rgb(0,0,0)">column++) { > > *rgba = osg::Vec4f(data, data, 0, 0); > > rgba++; > > } > > } > >// texture for sampler > >osg::ref_ptr<osg::TextureRectangle> textureRect = new osg::TextureRectangle; >textureRect->setTextureSize((int)subXRes, (int)subYRes); >textureRect->setInternalFormat(GL_RGBA); >textureRect->setImage(0, imageSampler);textureRect->setFilter(osg::Texture2D::MAG_FILTER, osg::Texture2D::NEAREST); >// configure shader > >stateset->addUniform(new osg::Uniform("textureID0", 0)); > >stateset->setTextureAttributeAndModes(0, textureRect, osg::StateAttribute::ON); > >// in fragment shader: > >uniform sampler2DRect textureID0; > > >void main() > >{ > > vec2 st=vec2(gl_FragCoord.x -0.5,gl_FragCoord.y-0.5); > > vec4 rgba = texelFetch(textureID0, ivec2(st)); > > Frag_Color = vec4(rgba.r,rgba.g,0,0); >} > >If I read the frame buffer, the value of rgba.r and rgba.g seem to be filtered value, not exactly what the real value. > >Where I am wrong here ? > >Thanks a lot! > >Best wishes >Shuiying >
_______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
