[osg-users] Properties in osg::Camera and values of gl_ModelViewMatrix seem out of sync.
Hi all,
Recently, I discovered a weird issue that the view/Proj matrix in the main
camera updated by the default cameramanipulator of osgViewer does not sync with
the one I got in the shader, e.g gl_ModelViewMatrix, gl_ProjectionMatrix.
The following two code snippets produce different results.
The first one is using the built in gl_ModelViewProjectionMatrix uniform passed
in during renderingTraversals()
The second one is using the properties from _viewer-getCamera() as uniforms,
e.g mainCamera-getViewMatrix().
Code:
void main()
{
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
}
Code:
uniform mat4 u_modelMatrix;
uniform mat4 u_viewMatrix;
uniform mat4 u_projMatrix;
mat4 getModelToWorldMatrix()
{
return osg_ViewMatrixInverse * gl_ModelViewMatrix;
}
void main()
{
gl_Position = u_projMatrix * u_viewMatrix * getModelToWorldMatrix() *
gl_Vertex;
}
When overlapping the rendering results of the two shaders into one buffer, the
second shader is approximately one frame slower than the first one, making me
doubt that the view/proj matrix managed by the main camera is not synced with
the one managed by the renderingTraversals().
This out of sync problem is also pronounced in Wang Rui's effectcompositor. In
the ssao.xml demo, if you turn on the analysis mode, you'll see that in the
linearDepth buffer view, the depth is unstable (flickering) when you zoom in
and out quickly.
The following is the code snippet from Rui's ssao.xml
Code:
void main(void)
{
vec4 vecInEye = gl_ModelViewMatrix * gl_Vertex;
depthValue = (-vecInEye.z - nearPlaneValue) / (farPlaneValue - nearPlaneValue);
gl_Position = ftransform();
}
I suspect that the nearPlaneValue and farPlaneValue form the built-in
projection matrix's uniforms are somehow not synced with the corresponding ones
in gl_ProjectionMatrix ( from ftransfrom() );
This problem bugs me for a long time. My current workaround is just using the
manually supplied uniforms from the main camera. But the extra computation of
the modelviewprojecionmatrix is definitely a waste in the vertex shader.
Any ideas?
Thank you.
...
Robin[/code]
--
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http://forum.openscenegraph.org/viewtopic.php?p=63199#63199
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Re: [osg-users] Render into a QQuickFramebufferObject (osg / osgEarth)
Hi Stefan, Thank you for your tips and hints, they were pointing me into the right direction! Especially the explanation how osg and osgearth handles the OpenGLContext was very useful for me! Great! Regards, Sascha -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=63201#63201 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Properties in osg::Camera and values of gl_ModelViewMatrix seem out of sync.
Hi Robin,
I'm a bit perplexed by the issue, as the uniform should be tracking the
modelview matrix directly as osg::State does a substitution.
Could you create a small code example that reproduces the problem?
Robert.
On 25 March 2015 at 01:28, Robin Wu wqxho...@hotmail.com wrote:
Hi all,
Recently, I discovered a weird issue that the view/Proj matrix in the main
camera updated by the default cameramanipulator of osgViewer does not sync
with the one I got in the shader, e.g gl_ModelViewMatrix,
gl_ProjectionMatrix.
The following two code snippets produce different results.
The first one is using the built in gl_ModelViewProjectionMatrix uniform
passed in during renderingTraversals()
The second one is using the properties from _viewer-getCamera() as
uniforms, e.g mainCamera-getViewMatrix().
Code:
void main()
{
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
}
Code:
uniform mat4 u_modelMatrix;
uniform mat4 u_viewMatrix;
uniform mat4 u_projMatrix;
mat4 getModelToWorldMatrix()
{
return osg_ViewMatrixInverse * gl_ModelViewMatrix;
}
void main()
{
gl_Position = u_projMatrix * u_viewMatrix * getModelToWorldMatrix() *
gl_Vertex;
}
When overlapping the rendering results of the two shaders into one buffer,
the second shader is approximately one frame slower than the first one,
making me doubt that the view/proj matrix managed by the main camera is not
synced with the one managed by the renderingTraversals().
This out of sync problem is also pronounced in Wang Rui's
effectcompositor. In the ssao.xml demo, if you turn on the analysis mode,
you'll see that in the linearDepth buffer view, the depth is unstable
(flickering) when you zoom in and out quickly.
The following is the code snippet from Rui's ssao.xml
Code:
void main(void)
{
vec4 vecInEye = gl_ModelViewMatrix * gl_Vertex;
depthValue = (-vecInEye.z - nearPlaneValue) / (farPlaneValue -
nearPlaneValue);
gl_Position = ftransform();
}
I suspect that the nearPlaneValue and farPlaneValue form the built-in
projection matrix's uniforms are somehow not synced with the corresponding
ones in gl_ProjectionMatrix ( from ftransfrom() );
This problem bugs me for a long time. My current workaround is just using
the manually supplied uniforms from the main camera. But the extra
computation of the modelviewprojecionmatrix is definitely a waste in the
vertex shader.
Any ideas?
Thank you.
...
Robin[/code]
--
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=63199#63199
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[osg-users] How to rotate a osg::Text heading when camera changes?
Hi, [Image: http://forum.osgearth.org/file/n7587273/无标题.jpg ] ... like pictures above,we use some icon to display a plane,this icon is osg::Text which using some special fonts file.we dynamic set this plane's heading to this osg::Text,like the left picture ,if the camera head to north,this osg::Text looks like head to the plane's heading.If we rotate the camera a bit ,like right pitcure ,it dosen't work. I know the reason,but not to know how to solve it .is there some way to re-computer the osg::Text heading when camera angle changes? Thank you! Cheers, Lv -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=63203#63203 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] flash the DatabasePager on demmand
Hi community, is there a way to flush (discard) the currently pending PagedLODs with a call? I read the class and didn;t found anything Thanks a bunch as always! Nick -- trajce nikolov nick ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] flash the DatabasePager on demmand
okay :-) .. maybe someone else will come up with a hint Thanks anyway Nick On Wed, Mar 25, 2015 at 6:51 PM, Robert Osfield robert.osfi...@gmail.com wrote: Hi Nick, I'm afraid I don't have any ideas off the top of my head. Too many other complex things on my table to handle pontificating on anything else complicated right now. Robert. On 25 March 2015 at 17:24, Trajce Nikolov NICK trajce.nikolov.n...@gmail.com wrote: Hi Robert, here is my situation. My client has large UTM database. Their IOS software needs to offset the database for each mission, so I have a NodeVisitor that apply some positinal offset to Geometry/Matrices/LODs. And there is a ReadCallback that uses this offset too. This works great, I can offset tiles that are loaded and to be loaded dynamically. However, I dont have control on the PagedLODs that are loading in between changing the offset, so these new tiles do not catch the correct offset. Any hint/hack for this situation? This is what I think is going on, not 100% sure though Thanks a lot! Nick On Wed, Mar 25, 2015 at 5:24 PM, Robert Osfield robert.osfi...@gmail.com wrote: HI Nick, I don't recall a method call to explicitly discards all pending DatabaseRequests. The DatabasePager discards DatabaseRequest's automatically if they aren't been refreshed by PagedLOD's that need them - this is done by tracking the frame number that of when the cull traversal hits a PagedLOD and requests a child. Robert. On 25 March 2015 at 16:04, Trajce Nikolov NICK trajce.nikolov.n...@gmail.com wrote: Hi community, is there a way to flush (discard) the currently pending PagedLODs with a call? I read the class and didn;t found anything Thanks a bunch as always! Nick -- trajce nikolov nick ___ 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 -- trajce nikolov nick ___ 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 -- trajce nikolov nick ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] flash the DatabasePager on demmand
HI Nick, I don't recall a method call to explicitly discards all pending DatabaseRequests. The DatabasePager discards DatabaseRequest's automatically if they aren't been refreshed by PagedLOD's that need them - this is done by tracking the frame number that of when the cull traversal hits a PagedLOD and requests a child. Robert. On 25 March 2015 at 16:04, Trajce Nikolov NICK trajce.nikolov.n...@gmail.com wrote: Hi community, is there a way to flush (discard) the currently pending PagedLODs with a call? I read the class and didn;t found anything Thanks a bunch as always! Nick -- trajce nikolov nick ___ 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] flash the DatabasePager on demmand
Hi Robert, here is my situation. My client has large UTM database. Their IOS software needs to offset the database for each mission, so I have a NodeVisitor that apply some positinal offset to Geometry/Matrices/LODs. And there is a ReadCallback that uses this offset too. This works great, I can offset tiles that are loaded and to be loaded dynamically. However, I dont have control on the PagedLODs that are loading in between changing the offset, so these new tiles do not catch the correct offset. Any hint/hack for this situation? This is what I think is going on, not 100% sure though Thanks a lot! Nick On Wed, Mar 25, 2015 at 5:24 PM, Robert Osfield robert.osfi...@gmail.com wrote: HI Nick, I don't recall a method call to explicitly discards all pending DatabaseRequests. The DatabasePager discards DatabaseRequest's automatically if they aren't been refreshed by PagedLOD's that need them - this is done by tracking the frame number that of when the cull traversal hits a PagedLOD and requests a child. Robert. On 25 March 2015 at 16:04, Trajce Nikolov NICK trajce.nikolov.n...@gmail.com wrote: Hi community, is there a way to flush (discard) the currently pending PagedLODs with a call? I read the class and didn;t found anything Thanks a bunch as always! Nick -- trajce nikolov nick ___ 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 -- trajce nikolov nick ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] flash the DatabasePager on demmand
Hi Nick, I'm afraid I don't have any ideas off the top of my head. Too many other complex things on my table to handle pontificating on anything else complicated right now. Robert. On 25 March 2015 at 17:24, Trajce Nikolov NICK trajce.nikolov.n...@gmail.com wrote: Hi Robert, here is my situation. My client has large UTM database. Their IOS software needs to offset the database for each mission, so I have a NodeVisitor that apply some positinal offset to Geometry/Matrices/LODs. And there is a ReadCallback that uses this offset too. This works great, I can offset tiles that are loaded and to be loaded dynamically. However, I dont have control on the PagedLODs that are loading in between changing the offset, so these new tiles do not catch the correct offset. Any hint/hack for this situation? This is what I think is going on, not 100% sure though Thanks a lot! Nick On Wed, Mar 25, 2015 at 5:24 PM, Robert Osfield robert.osfi...@gmail.com wrote: HI Nick, I don't recall a method call to explicitly discards all pending DatabaseRequests. The DatabasePager discards DatabaseRequest's automatically if they aren't been refreshed by PagedLOD's that need them - this is done by tracking the frame number that of when the cull traversal hits a PagedLOD and requests a child. Robert. On 25 March 2015 at 16:04, Trajce Nikolov NICK trajce.nikolov.n...@gmail.com wrote: Hi community, is there a way to flush (discard) the currently pending PagedLODs with a call? I read the class and didn;t found anything Thanks a bunch as always! Nick -- trajce nikolov nick ___ 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 -- trajce nikolov nick ___ 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
[osg-users] embed osgViewer into FLTK window...
All, I'm trying to embed an osgViewer that has a transparent background into an FLTK main window. The embedded osgViewer needs to have a transparent background so that I can see the parent window behind it. Is this even possible? What I'm trying to do is use the osgViewer as an overlay to render symbology on top of the main parent FLTK window. I've looked at the osgViewerFLTK example and the osgHUD example but nothing has worked so far. Any suggestions or help would be appreciated... Shayne -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=63209#63209 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] Negative Parallax
Hi, I am working in a research project where the scene is rendered in two TVs with a 120 degree angle between them. The objective is to emulate an hologram using 3d stereo vision and the fishtank formed by the TVs. I am setting each view with different view and projection matrices, similar as described in Generalized Perspective Projection by Robert Kooima, using slave cameras. My questions are regarding the following: 1) Is there any way to set a negative parallax to the entire scene while keeping fixed in the origin? This is necessary to keep the scene fixed, and the only view transforms are the rotation of the view frustums in order to align them with the TVs, as in the paper linked above. I've already tried billboarding, vextex shader program, and setting the fusionDistance. Any good results so far. 2) Is there any way to set the slave projection matrix (using the math described in the link), with non-perpendicular offsets (of the projection pyramid) so I keep the main projection transform in the main camera´s projection matrix (and use the standard slaveCallback, maybe)? Thank you! Cheers, Leonardo Ps. The image attached is old but shows the idea of the setup. -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=63210#63210 Attachments: http://forum.openscenegraph.org//files/stereo_frustum_165.png ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Properties in osg::Camera and values of gl_ModelViewMatrix seem out of sync.
Hi Robert,
Thank you for replying.
Here is the example code.
shader1.vert
Code:
#version 120
varying vec4 v_color;
void main()
{
v_color = gl_Color;
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
}
shader2.vert
Code:
#version 120
uniform mat4 u_viewMatrix;
uniform mat4 u_projMatrix;
uniform mat4 osg_ViewMatrixInverse;
varying vec4 v_color;
mat4 getModelToWorldMatrix()
{
return osg_ViewMatrixInverse * gl_ModelViewMatrix;
}
void main()
{
v_color = gl_Color;
gl_Position = u_projMatrix * u_viewMatrix * getModelToWorldMatrix() *
gl_Vertex;
}
shader.frag
Code:
#version 120
varying vec4 v_color;
void main()
{
gl_FragColor = v_color;
}
main.cpp
Code:
#include osgDB/ReadFile
#include osgViewer/Viewer
#include osg/StateAttributeCallback
#include osg/Shape
#include osg/ShapeDrawable
class StateNodeCallback : public osg::StateSet::Callback
{
public:
StateNodeCallback(osg::Camera *mainCamera) : _mainCamera(mainCamera) {}
virtual void operator () (osg::StateSet*ss, osg::NodeVisitor*nv)
{
ss-getUniform(u_projMatrix)-set(osg::Matrixf(_mainCamera-getProjectionMatrix()));
ss-getUniform(u_viewMatrix)-set(osg::Matrixf(_mainCamera-getViewMatrix()));
}
private:
osg::ref_ptrosg::Camera _mainCamera;
};
osg::Geode *createCylinder(const osg::Vec4 color)
{
osg::ref_ptrosg::Cylinder cylinder = new osg::Cylinder;
cylinder-setHeight(10.0f);
osg::ref_ptrosg::ShapeDrawable sd = new osg::ShapeDrawable;
sd-setShape(cylinder);
sd-setColor(color);
osg::ref_ptrosg::Geode geode = new osg::Geode;
geode-addDrawable(sd);
return geode.release();
}
int main()
{
osgViewer::Viewer viewer;
osg::ref_ptrosg::Geode cylinder1 = createCylinder(osg::Vec4(1, 0, 0,
1));
osg::ref_ptrosg::Geode cylinder2 = createCylinder(osg::Vec4(0, 1, 0,
1));
osg::ref_ptrosg::Program shader1 = new osg::Program();
shader1-addShader(osgDB::readShaderFile(shader1.vert));
shader1-addShader(osgDB::readShaderFile(shader.frag));
osg::ref_ptrosg::Program shader2 = new osg::Program();
shader2-addShader(osgDB::readShaderFile(shader2.vert));
shader2-addShader(osgDB::readShaderFile(shader.frag));
osg::ref_ptrosg::Group group1 = new osg::Group();
osg::ref_ptrosg::Group group2 = new osg::Group();
group1-addChild(cylinder1);
group2-addChild(cylinder2);
group1-getOrCreateStateSet()-setAttributeAndModes(shader1,
osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);
group2-getOrCreateStateSet()-setAttributeAndModes(shader2,
osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);
osg::ref_ptrosg::Camera mainCamera = viewer.getCamera();
group2-getOrCreateStateSet()-setUpdateCallback(new
StateNodeCallback(mainCamera));
group2-getOrCreateStateSet()-addUniform(new
osg::Uniform(u_projMatrix, osg::Matrixf(mainCamera-getProjectionMatrix(;
group2-getOrCreateStateSet()-addUniform(new
osg::Uniform(u_viewMatrix, osg::Matrixf(mainCamera-getViewMatrix(;
osg::ref_ptrosg::Group root = new osg::Group();
root-addChild(group1);
root-addChild(group2);
viewer.setSceneData(root);
viewer.run();
}
Make sure to set OSG_RUN_MAX_FRAME_RATE environment variable to a low value,
like 20, in order to better expose this issue.
I also attached a screen shot and the source code
...
Thank you!
Robin
robertosfield wrote:
Hi Robin,
I'm a bit perplexed by the issue, as the uniform should be tracking the
modelview matrix directly as osg::State does a substitution.
Could you create a small code example that reproduces the problem?
Robert.
On 25 March 2015 at 01:28, Robin Wu () wrote:
Hi all,
Recently, I discovered a weird issue that the view/Proj matrix in the main
camera updated by the default cameramanipulator of osgViewer does not sync
with the one I got in the shader, e.g gl_ModelViewMatrix,
gl_ProjectionMatrix.
The following two code snippets produce different results.
The first one is using the built in gl_ModelViewProjectionMatrix uniform
passed in during renderingTraversals()
The second one is using the properties from _viewer-getCamera() as
uniforms, e.g mainCamera-getViewMatrix().
Code:
void main()
{
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
}
Code:
uniform mat4 u_modelMatrix;
uniform mat4 u_viewMatrix;
uniform mat4 u_projMatrix;
mat4 getModelToWorldMatrix()
{
return osg_ViewMatrixInverse * gl_ModelViewMatrix;
}
void main()
{
gl_Position = u_projMatrix * u_viewMatrix * getModelToWorldMatrix() *
gl_Vertex;
}
When overlapping the rendering results of the two shaders into one buffer,
the second shader is
