Re: [osg-users] Help: Data accuracy from Frame buffer is not very good
Hi, On 29/11/2011 23:46, wang shuiying wrote: Hello, J.P. Delport I followed your advice but it still doesn't work well. And I also changed the internal format of the Image as GL_RGBA32F_ARB, but the points remain the same. What is the name of " the osgprerender example with the --hdr switch" ? the example is called "osgprerender", look at the code of it. It has a command line switch that enables HDR rendering to texture, but I'm not sure this is your problem anymore. What resolution are you expecting from the FBO and in what range are the vertex data you are using? Are you sure you are not converting to integers somewhere along the line? Are you using the osg::Image at all, or are you using the texture directly? rgds jp Thank you very much ! Shuiying ___ osg-users mailing list osg-users@lists.openscenegraph.org 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. ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Help: Data accuracy from Frame buffer is not very good
Hello, J.P. Delport I followed your advice but it still doesn't work well. And I also changed the internal format of the Image as GL_RGBA32F_ARB, but the points remain the same. What is the name of " the osgprerender example with the --hdr switch" ? Thank you very much ! Shuiying ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Help: Data accuracy from Frame buffer is not very good
Hi,
I'd suggest attaching a texture with a GL_RGBA32F_ARB internal format to
the camera as well (in addition to the image). I'm not sure you are
getting a float FBO. See the osgprerender example with the --hdr switch.
jp
On 29/11/2011 16:12, wang shuiying wrote:
Hallo,
I want to simulate laser scanner using osg camera. In Fragment shader
the color information is converted into position information. And then
the position information is accessed from this Fragment to be used to
draw points in a view. But the points are not so accurate, as it is
shown in the attached picture, which is composed of 11 cameras. The
important codes are:
osg::Program * program = new osg::Program();
program->addShader(osg::Shader::readShaderFile(osg::Shader::FRAGMENT,
fragmentShaderPath));
program->addShader(osg::Shader::readShaderFile(osg::Shader::VERTEX,
vertexShaderPath));
osg::Image * image = new osg::Image();
image->allocateImage(xRes, yRes, 1, GL_RGBA, GL_FLOAT);
osg::ref_ptr camera(new osg::CameraNode());
camera->setComputeNearFarMode(osg::Camera::DO_NOT_COMPUTE_NEAR_FAR);
camera->setViewport(0, 0, xRes, yRes);
camera->setClearColor(osg::Vec4(1000.0f, 1000.0f, 1000.0f, 1000.0f));
camera->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
camera->setProjectionMatrixAsFrustum(-tan( viewYaw), tan(viewYaw),
-tan(viewPitch), tan(viewPitch), zNear,zFar);
camera->setViewMatrix(osg::Matrix::lookAt(osg::Vec3d(0, 0, 1.0f),
osg::Vec3d(-10.0f, 0.0f, 0), osg::Vec3d(0, 0, 1)));
camera->setRenderOrder(osg::CameraNode::PRE_RENDER);
camera->setRenderTargetImplementation(renderTargetImplementation);
camera->attach(osg::CameraNode::COLOR_BUFFER, image);
camera->getOrCreateStateSet()->setAttribute(program,
osg::StateAttribute::ON);
In vertex Shader, I write:
void main()
{
x=(gl_ModelViewMatrix * (gl_Vertex - vec4(0.0,0.0,0.0,0.0))).x;
y=(gl_ModelViewMatrix * (gl_Vertex - vec4(0.0,0.0,0.0,0.0))).y;
z=(gl_ModelViewMatrix * (gl_Vertex - vec4(0.0,0.0,0.0,0.0))).z;
gl_Position = ftransform();
}
in Fragment shader, I write:
gl_FragColor = vec4(abs(z/100),abs(x/17),abs(y/4),0.2);
And I when get the position information, I will multiply them with the
corresponding factors.
However, the points are not that accurate. I seems that the Fragment
shader does not calculate the point one by one, but assign a certain
value to a certain amount of points.
Can anybody give some advice?
Thanks in advance!
Shuiying
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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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[osg-users] Help: Data accuracy from Frame buffer is not very good
Hallo,
I want to simulate laser scanner using osg camera. In Fragment shader
the color information is converted into position information. And then
the position information is accessed from this Fragment to be used to
draw points in a view. But the points are not so accurate, as it is
shown in the attached picture, which is composed of 11 cameras. The
important codes are:
osg::Program * program = new osg::Program();
program->addShader(osg::Shader::readShaderFile(osg::Shader::FRAGMENT,
fragmentShaderPath));
program->addShader(osg::Shader::readShaderFile(osg::Shader::VERTEX,
vertexShaderPath));
osg::Image * image = new osg::Image();
image->allocateImage(xRes, yRes, 1, GL_RGBA,
GL_FLOAT);
osg::ref_ptr camera(new
osg::CameraNode());
camera->setComputeNearFarMode(osg::Camera::DO_NOT_COMPUTE_NEAR_FAR);
camera->setViewport(0, 0, xRes, yRes);
camera->setClearColor(osg::Vec4(1000.0f, 1000.0f,
1000.0f, 1000.0f));
camera->setClearMask(GL_COLOR_BUFFER_BIT |
GL_DEPTH_BUFFER_BIT);
camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
camera->setProjectionMatrixAsFrustum(-tan(
viewYaw), tan(viewYaw), -tan(viewPitch), tan(viewPitch), zNear,zFar);
camera->setViewMatrix(osg::Matrix::lookAt(osg::Vec3d(0, 0, 1.0f),
osg::Vec3d(-10.0f, 0.0f, 0), osg::Vec3d(0, 0, 1)));
camera->setRenderOrder(osg::CameraNode::PRE_RENDER);
camera->setRenderTargetImplementation(renderTargetImplementation);
camera->attach(osg::CameraNode::COLOR_BUFFER,
image);
camera->getOrCreateStateSet()->setAttribute(program,
osg::StateAttribute::ON);
In vertex Shader, I write:
void main()
{
x=(gl_ModelViewMatrix * (gl_Vertex - vec4(0.0,0.0,0.0,0.0))).x;
y=(gl_ModelViewMatrix * (gl_Vertex - vec4(0.0,0.0,0.0,0.0))).y;
z=(gl_ModelViewMatrix * (gl_Vertex - vec4(0.0,0.0,0.0,0.0))).z;
gl_Position = ftransform();
}
in Fragment shader, I write:
gl_FragColor = vec4(abs(z/100),abs(x/17),abs(y/4),0.2);
And I when get the position information, I will multiply them with the
corresponding factors.
However, the points are not that accurate. I seems that the Fragment
shader does not calculate the point one by one, but assign a certain
value to a certain amount of points.
Can anybody give some advice?
Thanks in advance!
Shuiying
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